Is he flirting/does he like me?

So me (25m) and my roommate (27m) have lived together for almost 2 years. He’s honestly one of the funniest and sweetest guys I’ve ever met. He does however often call me “cute” or say I’m “his” (that part especially around our friend group) he constantly grabs or smacks my butt and honestly he does it to the rest of the friend group too but does it to me the most. I’ll sit on his lap sometimes or he will lay with his head on my lap sometimes even in public. He doesn’t directly tell people he’s straight but he also doesn’t directly tell people he’s gay. Even in the elevator the other day when we were surrounded by a bunch of people he turned around and looked at me and mouthed the word “cute”. He also stares at me a lot even when he thinks I’m not looking (or maybe he’s just zoning out? Idk.)

So I’m really confused. Does he like me? Is he flirting? Or am I just over thinking all this.