My best friend (22F) and her boyfriend (23M) have been together for two years. When they first got together, they were always trying to set me (22F) up with his brother(22M), but I never really entertained it—I’d just laugh it off. But at the start of this year, his brother and I ended up connecting on our own. We started hanging out, realized we had a good thing, and eventually started dating.

Now my best friend says it weirds her out, and there’s definitely been tension between us ever since. Part of me wonders if there’s some insecurity in her own relationship, because I can’t figure out why this would bother her so much. It almost feels like she sees herself as being “above” me in some way just because she’s been with her boyfriend longer. Like there’s some kind of hierarchy and I’m crossing a line I didn’t even know existed.

I actually thought it could be fun—most in-laws don’t get along, but we already had a friendship. Instead, she’s been acting distant and weird. Every time the situation gets brought up around others, she rolls her eyes or makes passive-aggressive comments. It’s upsetting, and our friendship hasn’t been the same since I started seeing him. It just feels so unnecessarily dramatic—like something out of high school.

I really like this guy and don’t want to stop seeing him, but I’m starting to feel stuck. So now I’m asking myself… am I the asshole for dating my best friend’s boyfriend’s brother?