What do i do about thiss!!!??? HELLP! =/?

Soo i just found out my bf's new roommate is a girl!! I mean i met her and she seems extremly friendly but heyy, imma girl and cann tell if another girl likes summ1! He says that they are only friends and i really dont have a problem with him being friends with gurls but living w/ them is another story..especially since he didnt tell meh about it until she moved in a week latter! PLUS she is sleeping in his room and he is sleeping "on tha couch" as he says. i say something to him about it and he says "yer overreacting bby, i only have eyes fer you." and now when i try ta call him or txt him he'll say that its rude to ignore his company actually tlkin about his new "**roomie**".....am i ovverreacting or should i be mad!? AHHHHHH!!!! D: