Step mom ?

Christina • 18years. Happily taken. 💕☮
So I've been in a pretty serious relationship w/ a guy who has 2 beautiful boys. Can anyone give any advice to help w/ baby momma drama or how I should act ? Like diciplining his kids ect. ? I'm not a parent so I'm not sure how to act like one. Don't get me wrong, I love his children but I don't really know where my boundaries are & things like that. Plus his baby momma puts a lot of stress on our relationship because she's super jealous & still in love w/ him. So it can get really difficult for me & him. & he said I'm not aloud to beat her ass, so I need a more civil way of dealing w/ her. 🙄☺️