Is this an "alpha male" flirting sign?

There is a guy I like and I get the feeling it's mutual. But it's hard to tell sometimes men play such silly mind games and it drives me nuts. Anyways I was talking in a small room with my friend and he was there and came in And sat on the couch in front of us and listened to our convo and would sometimes join in on the talk. Now when he sat down on the couch he kept his legs open and sat back into the couch and then put his hands behind his head. Then he proceeded to keep glancing my way at times I caught him checking out my legs and waist area a couples times. Is this a typical flirting move that guys do? Is is he just being comfy? I just found it kind of odd doing that in a room with two girls and himself.

Is this an "alpha male" flirting sign?
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