delivered the opinion of the court:
In March 1995, the trial court entered a judgment dissolving the *777marriage between petitioner, Rhonda K. Houghton, and respondent, Walter W Houghton, and granting Walter sole custody of their daughter, Destiny. In May 1996, pursuant to an agreement between Walter and Rhonda, the court granted Rhonda sole custody of Destiny. In December 1997, following Rhonda’s death, the trial court granted the petition of intervenor, Maurine Kay Winkler (Kay), Rhonda’s mother, to modify custody and to make Kay Destiny’s custodian.
Walter appeals, arguing that (1) Kay lacked standing under section 601(b)(2) of the Illinois Marriage and Dissolution of Marriage Act (Act) (750 ILCS 5/601(b) (2) (West 1996)) to file a petition to modify custody; (2) the trial court’s order was void because Kay never filed a petition to modify custody; and (3) the court erred by (a) granting Kay’s petition to modify custody, and (b) restricting Walter’s visitation with Destiny. We agree with Walter’s first argument and reverse.
I. BACKGROUND
Because the parties are familiar with the evidence presented during the hearing on Kay’s petition, we discuss it only to the extent necessary to put Walter’s lack of standing argument in context.
Walter and Rhonda were married in April 1991. During their marriage, they had one child, Destiny, born March 21, 1994. In June 1994, Walter began serving a two-year prison sentence for obstructing a police officer. Kay testified that while Walter was in prison, Destiny stayed at Kay’s home. Kay stated that “[o]nce in awhile[,] Rhonda would come and get her, but not very often.”
In October 1994, Rhonda filed a petition for dissolution of marriage, and in November 1994, Walter filed a cross-petition for dissolution of marriage. In December 1994, Walter was released from prison. Immediately upon his release, Walter picked up Destiny from her baby-sitter, and Destiny once again began living with Walter. During that same month, Rhonda dismissed her dissolution petition because she and Walter had reconciled. However, Walter proceeded with his cross-petition, and in March 1995, the trial court entered a judgment dissolving the marriage and granting Walter sole custody of Destiny.
Following their divorce, Walter and Rhonda reconciled and lived together off and on. From the time of the dissolution judgment in March 1995 until May 1996, Walter was Destiny’s sole legal custodian. Throughout most of that time, Destiny also lived with him. Kay testified that in February 1996, Walter dropped off Rhonda and Destiny at Kay’s home, and he did not pick them up until May 1996. Walter disputed this, claiming that he took Rhonda and Destiny to Kay’s home because Rhonda wanted to move out. He agreed that Rhonda could keep Destiny with her for two weeks. When Rhonda refused to *778bring Destiny back to him at the end of the two-week period, Walter asked the Adams County sheriffs department to retrieve Destiny for him, and it did.
In May 1996, Walter and Rhonda agreed that Rhonda could have sole custody of Destiny, and they filed a joint petition to modify custody accordingly. Pursuant to their agreement, the trial court granted the petition and awarded Rhonda sole custody of Destiny. Walter testified that he agreed to transfer custody of Destiny to Rhonda because he and Rhonda were going to remarry and “Rhonda basically wanted that as *** some sort of a nail in the wall to hold otir relationship together.” Between May 1996 and March 1997, Walter and Rhonda lived together off and on. Although Destiny usually lived with Rhonda during that time period, Kay testified that Walter sometimes had “physical custody” of Destiny as opposed to Rhonda.
On March 9, 1997, Rhonda died in an automobile accident. Later that same day, Walter located Destiny, who had been staying with some nonrelatives, and took her to live with him. On March 25, 1997, Walter filed a petition to reestablish his custody of Destiny, which the trial court granted. From the time of Rhonda’s death until the trial court’s granting of Kay’s petition to modify custody in December 1997, Destiny lived with Walter and visited with Kay every other weekend, pursuant to an agreement between Walter and Kay.
In November 1997, the trial court conducted a hearing on Kay’s petition. In December 1997, the court granted the petition, awarded Kay custody of Destiny, and granted Walter restricted visitation with Destiny. This appeal followed.
II. ANALYSIS
A. The Petition To Modify Custody
Initially, we note Walter’s argument that the trial court’s December 1997 order was void because Kay never filed a petition to modify custody in these .proceedings. Kay concedes that the record here does not contain a copy of her petition to modify custody that had been file-stamped by the clerk of court. Nonetheless, she contends that the record indicates that she actually filed her petition. Specifically, she points to the following: (1) a June 1997 written order specifically mentioned a “[pjetition to [mjodify filed by M. Kay Winkler”; (2) in August 1997, Walter filed a motion to continue which stated that “[tjhere is currently pending before this [cjourt a [mjotion to [cjhange [cjustody of the parties’ minor child from the father to the maternal grandmother”; and (3) the record discloses no objection or complaint from Walter that he had not received a copy of Kay’s petition.
Although it appears that Kay’s response to Walter’s argument *779that she never filed a petition to modify custody may be soundly based, we decline to address it further. Because of our resolution of this case, we need not decide this matter.
B. Standing
Walter also argues that Kay lacked standing under section 601(b)(2) of the Act (750 ILCS 5/601(b)(2) (West 1996)) to file a petition to modify custody. In response, Kay argues that Walter has forfeited the issue of standing by failing to raise it until after the November 1997 hearing on Kay’s petition. Alternatively, Kay argues that she had standing under section 601(b)(2). We agree with Walter that Kay lacked standing.
1. Forfeiture
Lack of standing under section 601(b)(2) of the Act is an affirmative defense which is forfeited unless raised in a motion to dismiss during the time for pleading. In re Marriage of Sechrest, 202 Ill. App. 3d 865, 874, 560 N.E.2d 1212, 1217 (1990). In Sechrest, 202 Ill. App. 3d at 875, 560 N.E.2d at 1218, this court held that the natural parent had forfeited the issue of standing by raising the issue for the first time in a posttrial motion after three years had passed with the child in the custody of third parties. In so holding, this court wrote the following:
“We seek to make clear under the Act the Kennedys, as third parties, did not have standing to petition for custody of [the child]. To prevent such situations in the future, trial courts must carefully examine the pleadings and may, sua sponte if necessary, raise the issue of a nonparent’s standing or lack of standing.” (Emphasis added.) Sechrest, 202 Ill. App. 3d at 875, 560 N.E.2d at 1218.
In the present case, it is undisputed that Walter first raised the issue of Kay’s lack of standing in a motion to reconsider the trial court’s December 1997 order granting her petition. However, despite Walter’s failure to raise the standing issue at the November 1997 hearing, evidence was presented on that issue at that hearing, and the court specifically addressed it in its subsequent ruling. In its December 1997 written order, the court specifically found that “the maternal grandmother herein [(Kay)] has standing to pursue her [p]etition to [m]odify pursuant to the requirements of [s]ection 601(b)(2) of the [Act].”
We commend the court for addressing this issue, consistent with this court’s decision in Sechrest. Thus, because the court sua sponte addressed and ruled upon the issue of Kay’s standing under section 601(b)(2) of the Act, we conclude that Walter has not forfeited that issue.
*780Our conclusion is consistent with the underlying purpose of the forfeiture doctrine — that is, to preserve finite judicial resources by creating an incentive for litigants to bring issues to the trial courts’ attention, thereby giving courts an opportunity to consider those issues. See People v. McKay, 282 Ill. App. 3d 108, 111, 668 N.E.2d 580, 583 (1996). As earlier discussed, although Walter did not bring the issue of standing to the trial court’s attention, the court — by its own initiative — did consider the issue. Moreover, we note that the court’s sua sponte consideration of Kay’s standing under section 601(b)(2) of the Act comports with the notion that the termination of parental rights is an extraordinary measure that may warrant considering issues without resorting to doctrines of judicial convenience, such as forfeiture. See In re Y.B., 285 Ill. App. 3d 385, 390, 674 N.E.2d 819, 821-22 (1996).
In addition, we note that Kay does not contend on appeal (nor did she before the trial court, for that matter) that she would suffer prejudice if the issue of standing was deemed not forfeited. See In re Custody of McCarthy, 157 Ill. App. 3d 377, 380-81, 510 N.E.2d 555, 557 (1987) (trial court has discretion to allow tardy filing of a motion to dismiss challenging standing unless it can be demonstrated that the opposing party was prejudiced by the late filing).
Although we conclude that Walter has not forfeited the issue of Kay’s lack of standing, we nonetheless do not condone his failure to raise the issue in a timely motion to dismiss.
2. Merits
Section 601(b)(2) of the Act provides, in relevant part, as follows:
“(b) A child custody proceeding is commenced in the court:
(2) by a person other than a parent, by filing a petition for custody of the child *** but only if he is not in the physical custody of one of his parents.” (Emphasis added.) 750 ILCS 5/601(b)(2) (West 1996).
The superior right of a natural parent to custody of his child is recognized and protected in the Act by requiring a nonparent seeking custody to meet the standing requirement embodied in section 601(b)(2) of the Act (750 ILCS 5/601(b)(2) (West 1996)) before being considered for custody under the best interests standard set forth in section 602 of the Act (750 ILCS 5/602 (West 1996)). See In re Petition of Kirchner, 164 Ill. 2d 468, 491, 649 N.E.2d 324, 334-35 (1995); In re Marriage of Brownfield, 283 Ill. App. 3d 728, 732, 670 N.E.2d 1198, 1201 (1996). To establish standing, a nonparent has the burden of showing that a child is “not in the physical custody of one of his *781parents” before she can seek custody of the child. 750 ILCS 5/601(b)(2) (West 1996); see also Kirchner, 164 Ill. 2d at 490-91, 649 N.E.2d at 334-35; In re Marriage of Rudsell, 291 Ill. App. 3d 626, 632, 684 N.E.2d 421, 425 (1997).
The determination that a parent does not have physical custody of his child turns not on possession; rather, it requires that that parent “somehow has voluntarily and indefinitely relinquished custody of the child.” (Emphasis added.) Kirchner, 164 Ill. 2d at 491, 649 N.E.2d at 335; see also In re Custody of Peterson, 112 Ill. 2d 48, 52-53, 491 N.E.2d 1150, 1152 (1986). However, not every voluntary turnover of a child will deprive the parent of physical custody. The trial court must consider factors such as (1) who was responsible for the care and welfare of the child prior to the initiation of custody proceedings; (2) the manner in which physical possession of a child was acquired; and (3) the nature and duration of the possession. See Kirchner, 164 Ill. 2d at 493, 649 N.E.2d at 336; Rudsell, 291 Ill. App. 3d at 632, 684 N.E.2d at 425. A reviewing court will disturb a trial court’s decision in a custody proceeding only if it was against the manifest weight of the evidence or will result in manifest injustice. Franklin v. DeVriendt, 288 Ill. App. 3d 651, 655-56, 681 N.E.2d 578, 581 (1997).
The record is clear that Walter never “voluntarily and indefinitely” relinquished his right to the care, custody, and control of Destiny. Even assuming that Rhonda had relinquished physical custody of Destiny to Kay while Walter was imprisoned between June 1996 and December 1996 (when Rhonda and Walter were still married), Rhonda’s unilateral relinquishment could not be imputed to Walter. See Kirchner, 164 Ill. 2d at 493, 649 N.E.2d at 335 (“A unilateral relinquishment by one parent cannot serve as the basis for establishing standing under section 601(b)(2) as against the other parent”). In addition, both Kay and Walter testified that immediately upon Walter’s release from prison in December, he retrieved Destiny from her baby-sitter and took her to live with him and Rhonda.
We also reject Kay’s contention that Walter voluntarily and indefinitely relinquished physical custody of Destiny to her when he left Rhonda and Destiny at Kay’s home in February 1996. The length of time Rhonda and Destiny stayed with Kay is disputed (according to Kay, it was three months; according to Walter, it was two weeks). Regardless, considering that Walter had sole legal custody of Destiny at that time and Rhonda continued to live with Destiny, it would be unreasonable to expect Walter to think that Kay had physical custody of Destiny. Moreover, it is undisputed that Walter exhibited interest in Destiny when he secured the assistance of the sheriffs department to retrieve her from Kay’s residence.
*782In May 1996, Walter agreed to transfer custody of Destiny to Rhonda because he wanted to remarry Rhonda, and Rhonda wanted some showing of his sincerity. Following Walter and Rhonda’s agreement to transfer custody of Destiny to Rhonda, Walter and Rhonda lived together off and on until Rhonda’s death in March 1997. Kay acknowledged that during that time period, Walter sometimes had “physical custody” of Destiny as opposed to Rhonda. Importantly, even when Walter and Rhonda were not living together during that time period, Rhonda and Destiny never lived with Kay. Instead, Destiny simply visited her on weekends and some weekdays.
“ ‘Overnight contact with third parties fails to fulfill the statutory provision that the child not be in the physical custody of one of her parents. *** We do not accept petitioner’s theory that physical custody may be relinquished by default if a parent performs the task of parenting in a less than adequate manner.’ ” Sechrest, 202 Ill. App. 3d at 873, 560 N.E.2d at 1216-17, quoting In re Custody of Barokas, 109 Ill. App. 3d 536, 544, 440 N.E.2d 1036, 1042 (1982).
See also In re Custody of O’Rourke, 160 Ill. App. 3d 584, 587, 514 N.E.2d 6, 8 (1987) (despite third parties’ weekly and often daily care of the children, the legal custody of the children remained with the mother until her death, at which point it transferred to the father).
On March 9, 1997, the day Rhonda died, Walter found Destiny at a nonrelative’s house and took her to live with him. On March 25, 1997, Walter filed a petition to reestablish custody of Destiny, which the trial court granted. See In re Marriage of Gustafson, 181 Ill. App. 3d 472, 481, 536 N.E.2d 1359, 1364 (1989) (Green, J., specially concurring) (if a noncustodial parent consistently shows interest in his child and promptly seeks custody upon the death of the custodial parent, courts will imply a constructive physical custody in favor of the noncustodial-parent).
We acknowledge the deferential standard under which we must review a trial court’s decision in a custody proceeding. However, after carefully reviewing the record before us in accordance with the appropriate standard of review, we conclude that the court’s finding that Kay had standing under section 601(b)(2) of the Act (750 ILCS 5/601(b)(2) (West 1996)) because Walter had voluntarily relinquished custody of Destiny was against the manifest weight of the evidence.
*783III. CONCLUSION
For the reasons stated, we reverse the trial court’s judgment.
Reversed.
KNECHT, J., concurs.