Need advice on how to deal with boyfriends kids sleeping arrangement

My boyfriend and I live in a 2 bedroom apartment. His 2 daughters (9 and 5 years old) stay with us Fri-Sun for 3 weekends every month (so a total of 9 nights every month). Lately they have been insisting on sleeping on the couch every night that they’re here. They have a bedroom that has 2 beds in it for them but they don’t want to sleep in there. This bothers me and my boyfriend doesn’t think it’s a big deal. Am I overreacting? I just think it’s dumb we’re paying for a 2 bedroom apartment when they aren’t using it at all. Note before we moved in, I asked him if he thought we for sure needed a 2 bedroom because I thought this might happen. He told me we definitely needed to have a bedroom for them.

Ofc I'm here because this sounds like a dumb problem. The kids want to sleep outside. You resist. They persist. Your husband doesn't give a damn. Just let them be. You'll see. Or convince husband to back you up and act as one force, then they'll listen, obv. Easy, done, next.