I only voted no because of the 15yo.
I just feel like he's not gonna be as easily impressed by the man fucking his mom as the younger ones.
He could be a really sweet 15yo who is capable of expressing complex emotions about his mom's love life without acting out but...even adults have issues with that.
Yall remember the song "step daddy"?
https://youtu.be/xLzvgGvlOTA