no strings attached

I've been sleeping with this guy, and it was an established "just sex" situation, we hang out, have sex, maybe watch a movie... lately he's asked me to go out on his boat a few times, but never any real date stuff. He's a total flake and he's kind of an asshole to begin with, but he's warmed up to me, except lately he turns into hyper-asshole immediately after sex. Like cops an attitude as soon as his dick is out of me. I tried being cute, cuddling up to him, thinking maybe he'd chill, but I'm not the type to deal with an attitude like that for long. Last night I stood up amd walked out with a cool but pointed, "Bye!" and he says, "Woah anger" ... I told him I'm just being the way he is to me. Yes, before you assume or ask anymore - I do have some stupid feelings for him. WTF is with this behavior?? For the record this guy is no where near out of my league, if anything I'm way out of his. Is this a power trip thing?