Objective. A multi-phase, sequential mixed methods study aimed to determine acceptable age-appropriate physical intimate behaviors shared between Filipino parents and children that are related to hygiene, affection and privacy.
 Methods. Following an exploratory qualitative phase (Phase 1) and an instrumentation phase (Phase 2), the quantitative survey phase (Phase 3) utilized the resultant Filipino Family Behavior Questionnaire (FFBQ). A total of 145 participants from Cabuyao, Laguna and selected urban communities in Metro Manila were comprised of 72 parents and 73 adult children.
 Results. Parents and adult children view the affection-related behaviors of hugging (magyakapan/ magyapusan) and kissing on the cheeks (humalik sa pisngi) as most acceptable among the list of parent-child intimate behaviors in the FFBQ, and is allowed without any age limit set for children (up to age 18 years). The lowest accepted age-appropriate intimate behaviors were hygiene related, specifically on washing genitalia (median 5 years, range 0,18), co-bathing (3 years, range 0,18), and holding/kissing genitals (0, range 0,17). Generally, adult children accept higher age-limits compared to parent participants. Both groups placed higher age-acceptable limits on mothers compared to fathers.
 When comparing parent-child pairs, same-gender pairs have significantly higher age-acceptable limits compared to mixed gender pairs. Ranked in order of highest to lowest age-acceptable limits, the most accepted gender pair in performing intimate behavior is mother-daughter; father-son; mother-son; and father-daughter. Perceptions of acceptable age limits were comparable between parents with adverse childhood experiences (ACEs) compared to those without ACE, except for hugging between mother-daughter (17.21 vs 18 years, p=0.04) and father-daughter (17.21 vs 14.22 years, p<0.01) as well as co-dressing of mother-son (3.76 vs 2.19 years, p=0.02).For children, differences in perception were noted only for hugging between mother and son (17.95 vs 15.37 years, p<0.01), and kissing on lips between father and son (5.33 vs 8.94 years, p=0.03). Respondents in Phase 4 believe that mothers are seen as nurturing and caring towards children, thus rendering acceptance of higher age limits for engaging in intimate behavior, specifically for hygiene and privacy. Similar-gender pairs tend to be more at ease with each other, hence the persistence of intimate behavior even at older ages.
 Conclusion. This study was able to identify Filipino intimate behaviors of parents and children including their age-appropriateness. Parents and adult children had similar valuations for healthy boundaries in intimate behavior, as evidenced by the older perceived mean ages for hugging, kissing on the cheek (affection) and co-sleeping (privacy), as well as younger perceived mean ages for hygiene-related intimate behavior such as holding/kissing genitalia, washing genitalia and co-bathing. Parent-child intimate behavior is more acceptable for same-gender pairs, and is least appropriate for older ages in father-daughter pairs. Moreover, adult children appear to be more permissible in exhibiting lower cutoffs for age limits of acceptability compared to parents.