<human>: Okay, so here's the situation(sorry it's long): I've been living with this girl now for a little over a year, we started as best friends but like most living situations go we have had a lot of drama and grown apart. Recently her boyfriend moved here from out of state and I ended up dating his best friend, which while fun at times, has caused some weird tension. She constantly feels the need to give me advice and put down my relationship and boyfriend when I have clearly not requested her input.

All of that aside, lately she has been hanging out with this other guy who she used to have hook up with frequently. Although I doubt she would ever cheat and really does love her bf, the whole situation is very sketchy. They go out just the two of them and come back home at 2am, totally wasted. They make dinner together and hang out one on one at his place. Normally, I would overlook all this, but the thing that really concerns me is that she isn't honest with her bf about how much time she spends with this dude or their past history together. She says it is just better left unsaid, although I know if the tables were turned she would be livid.

Anyway, the last time I was with my boyfriend the dude starts texting and calling me to see where she is (and this is not the first time). My bf was not too thrilled and asked who it was so I gave him a very brief explanation, a decision I came to regret. He immediately wanted to tell her bf/his best friend, which I convinced him would be a bad idea, seeing as I really don't think anything would happen between them. He told me he wants me to talk to her or he wants to talk to her bf, but I'm not exactly sure what to tell her, she knows what she is doing and refuses to stop.

Also, she will make my life living hell, she is already an awful roommate (doesn't clean/do dishes/take out trash) but I just know she would become worse.

I'm not sure what to do at this point, so any thoughts and advice would be cool.

Can you summarize the given text in a few sentences?
<bot>: Roommate is acting sketchy with some new dude, and I'm not sure if I should talk to her or her bf about it.