Does "at BF's" mean best friend or boyfriend? ( would like womens answer)?

i Know it means different things...Im just wondering because i have the biggest crush on this chick in my College Math class...I just texted her , i asked her if she was working and she said no just at the bf"s house...Now since i am completely in love with her and she probably doesn't know it.... i was just analyzing and over thinking it as any guy that has been struck by that demon vermin, Cupid. I could ask her if she has a boyfriend...but that would just be weird. (on my behalf)