My bf wants to spend the night at his boyfriends house and we only live 45 minutes from here. Is this normal?

My boyfriend and I have ben living together for over 4 years now. One of his boyfriends who just kicked his girlfriend out wants him to go and spend the night at his house. he even has a bedroom for him and put his name on the door. We only live 45 minutes from there, so why is it so important to spend the night at his house. You are talking about grown men in their 60's. We fought about this a few months ago. This guy sent my boyfriend a romantic poem for a birthday card. I think this is creepy? My boyfriend and have spent a few nights apart that was only because we were away and i mean away. Hours apart. I believe his friend is once again trying to split us apart. Funny things is my bf can not live with him because he is a clean freak and he can not even take his dog with him so I have to watch his dog. If 2 people love each other and live together why in the world would you want to spend a night apart?