It sucks that this game developes more and more into "how do i let other guys fuck my women".
With the possible implied exception of John, who is Jason's adoptive father and Janice's
husband, and Rachel and Rebecca's
husbands, no other male character is having sex with "your women" unless you want them to.
With Janice it's also implied that when John's home, she's not having any sex that isn't with Jason or Jason and Julia.
Given that if you choose not to have Jason and Janice screwing behind John's back when he's at home for a week, she's absolutely gagging for it and takes Jason to her own bedroom immediately after John leaves the house.
In the cases of Rebecca and Rachel, Jason is already a better lover in bed than their husbands, and they look forward to him more than their own husbands.
Getting jealous over married pixels is pretty funny, especially when their husbands are the ones getting cucked, and not the Player Character
At the end of the day, every relationship Jason has with each of the women is pretty much nothing more than sexual.
Janice and Julia are possible exceptions, since both speak of how much they love/are falling in love with Jason, although this is during sex and people say these kinds of things "in the heat of the moment" without actually meaning it.
Basically, not one woman in the game is "yours" or Jason's.
He's a school kid, has no stable income and is in the worst possible position to even try and support himself and any one of the multiple women he gets to have sex with.