well...give u a hug...
I dont know how to say...
When I first came here, I kind of had the same trouble...my roommate was a black girl that alway brought different guys back to our dorm...sometime they just talk...that's fine...but sometime, they even watch AV or do something together...>_<...which made me really annoyed...but I can't really do anything...but tell the RA who responsible for keep everyboday's right in the dorm...
Evantually I moved to somewhere else...
As others said, you can ignore it...or try something out...
Whatever you choose...Just don't make yourself such unhappy because of that...