Boyfriend poss having bachlor party?

So my boyfriends brother is getting married tommorow and today is the rehersal. My boyfriend called me when I got off work today and told me that him his brother and cousin are spending the night at his grandmas tonite because his brother doesnt want to see his fiancee till tommorow at the alter. My boyfriend told me on the phone that I could come stay with him tonite but as soon as he said that his brother yelled in the backround "No, no girls"...I asked him what they were planning on doing since his brother didnt want any girls there and my bf said they had nothing planned and that he thinks his brother was j/k about it and that if I wanted to stay with him I could. Of course I would not feel comfortable there knowing what his bro said earlier but I just worry that he isnt telling me something that they have planned for tonite because why wouldnt he want any girls there? I just worry that something might happened like them going out and getting strippers or go out and get shitty drunk which my bf is a HORRIBLE drunk and something bad always happens when he does which is why he quit when he met me but has had slip ups in the past. Its driving me nuts that I have to spend the night alone at our apartment not knowing what they might do or if he is hiding something from me. Any girls out there went through this with their boyfriends? Please no harsh answers, I'm not trying to sound insecure but this is really bothering me because it all the sudden just "came up" today