I get how stressful this is. I dated a roommate's ex-boyfriend. She said she was long over him (it had been 10 years since she dated him) but she was very jealous of our relationship.

I had another roommate who really liked a guy but he only wanted to be friends with her, he wanted to date me. We did go out a couple of times but it was stressful on me and so I dropped things. It sucked as I think the guy was good for me. I wish I had done what was right for me instead of letting guilt make my decision.