what the hell do I do?

So last year my bf invited me very late to be his date to a party. It was drinking so he had a hotel room with his friend. I was a little stranger out because I never met this guy before but he was nice and polite to me. I figured it was one night and we wouldn't spend much time in the room besides sleeping so I didn't complain. Well now my bf has decided to share the room again with this guy and already paid his half. He said I could come but honestly why wouldn't he ask me if it's okay to stay with another guy. I want to be alone with my bf. I wouldn't mind paying half the hotel so we were alone. It's not a financial thing either because he works so much and spends money so easily. Why would he think it's okay to have another guy stay with us? He said it's the same guy as last year but I don't think it can be since he has been across the country for the last few months and his program will still be going on by the time of the date. Do I sound like a snob if I tell him no to staying with him?