Now, this happens to some of us guys i think. For instance, babes, especially some very pretty ones, may just come and sit around me in class, and the next thing i notice is that a comfortable me b4 suddenly becomes breathless and sweating through the armpits! Guys, why does this usually happens nao?

Introvert

maybe because of sexual feelings,

I dnt feel awkward or uncomfortable so I cnt say y some guys feel dat way.

Guess most times it's due to Lack of Self confidence...Guys get intimidated and lose their composure just because of the presence of another(this time, the opposite sex).
It's not Ideal,..
There was a time I battled with that alot but overtime I had to Tell myself the Truth.
First, you need to stop trying to get Other People's attention...Stop, Stop It..
When a man is deeply settled and composed within on who and what he is; not trying to act Unreal 'cos of the presence of a lady;Believe me, such guys would Get the respect and admiration from the female folks..
Such kind of a guy cant be turned into a "maga";It's not Pride, It's packaging

Well, I had a different experience with babes. Whenever I got to the lecture hall in those days on campus, they always watched out for where I was gonna sit. Immediately I grabed a place, all the ladies around will beat it. And sometimes, those who refused to scram, I tell them to beat it myself, and they always did. They hated my gut and I did not give a damn. Up till now, even though I now smile with ladies, 99 per cent of those I smile with always know I am faking it. They are always careful about over stepping their boundaries. Who has time for bullshhits? Mtcheeew.