Tight clothes on a guy is fine but I do feel it depends on where. I wear sweat gear at the gym and it's tight but the chances of me wearing it elsewhere is not much as it would seem out to place to me. Anyone who naturally assumes cocky and all that stuff without getting to know the person I feel is insecure. I don't see it cocky at all when in the right place. Cocky can be judged by their body language and how they act as a person. If anyone(guy or girl) is wearing revealing clothing in freezing cold weather then I think "Why...? It's freezing out!" and would assume they are trying too hard.
Like I wear a tank sometimes but with it being winter it's stashed away and maybe I will wear it to the gym once in a blue moon. When spring and summer roll around I'll bring it out again. There's nothing wrong with a guy wearing what he wants. Girls do it all the time so for a girl to judge a guy negatively over clothing is hypocritial since girls love showing off their bodies all the time. We got girls showing off cleavage everywhere. Some guys assume she's easy and others don't. Same applies with this.
honestly I'm decently built, I'm 5'9 175, and with my proportions all my shirts are fitted whether they are cut that way or not. a small is way too small, and a large is way too big, medium is just right.
button downs suck though I can't even lift my f***ing arms in them