Friend help

Sometime I feel like the odd person out my roommates are all friends from before and we all got super close but two of them are inseparable. When we’re all together they’re just having conversations with each other in front of the other two of us. It never used to be like this and I feel like sometimes it can be awkward between us. I don’t know what to do should I say something? I’ve been wanting to but I’m too scared I don’t want to upset anyone