Boyfriend sleeping on the couch

Back history: my boyfriend (27) and I(27) have been together for 3 years . We don’t live together but we are always together . He likes to hangout at his cousins house and when he’s drinking he usually spends the night and sleeps on the sofa at least four times out the month.

I haven’t been over in his cousins house in a long time. Well I finally went over and everyone got to talking . So apparently his cousins (20 ) best friend needed A place to stay so she’s been living with them until just last week when she found out her best friend slept with her uncle while he was in town . But then they pointed out she didn’t have a room and slept on the couch the four months staying there. It’s just weird to me because he always slept on the couch . Am I overthinking this ? I haven’t asked him much but it’s in the back of my mind.

You guys are all absolutely right down to the communication. It is weird how he never mentioned it and honestly I never thought about it as if he wasn’t staying there.