She’s in a near occasion of sin for several reasons.
- Because her roommate is knowingly torquing her off. This brings her to a near occasion of the sin of wrath, the sin of striking her roomie, the sin of brooding and thinking up creepy passive-aggressive stuff to do to her, etc.
- Because the roommate keeps expecting everybody to be okay with this, there’s the near occasion of the sin of falling in with peer pressure, lying, succumbing to cognitive dissonance and agreeing that pre-marital sex is no big deal, etc.
- If the roommate is having sex on the other side of the wall, obviously this can cause a lot of near occasions of sin: wrath, envy, lust, etc. It is freaking annoying to try to sleep through that sort of noise, too.
- Not very much fun living with somebody who keeps trying to abort herself. And with herbs, which are not exactly a model of safety and effectiveness for anything. Like the Ovid poem says, nothing like trying to murder yourself and your baby all at the same time.
Finally - even though this guy is apparently nice enough, there’s a lot more danger of sexual assault from a boyfriend of somebody else living in your place than of total strangers going after you. Heck, when I did a college visit as a teenager ages ago, I had somebody’s drunken boyfriend try to assault me on my first night sleeping in the place! Not a joke!
Obviously that’s not a near occasion of sin, other than the sin of murdering the jerk, but I’d rather not be the object of somebody else’s violent assault or rape type of sin, thank you very much.