DF is my boyfriend and we've been together for 1 year and 6 months. 

BD is a girl who was an old friend but moved away now she's been back for maybe a year. Since she's been back we haven't hung out or even really seen each other. when we do see each other we speak but that's it. 

Anyway so BD is now "really good friends" with my boyfriend, DF, like she calls him her brother and stuff. But that isn't what bothers me. It's the fact that she's over his house every single day and sometimes spends the night. she sleeps down stair and he sleeps up stairs in his bed but still. it the fact that she's always over there and she spending the night. not that I'm worried about my boyfriend, DF cheating on me because I really do trust him, it's just what people think and say. she also post stuff all over social media. 

Am I being crazy or real?