You should treat girls as individuals. Don't take revenge for one girl out on another, just because they are members of the same sex doesn't mean they have the same intentions. If they are with you now, they put themselves on the line and in some way are risking it to be with you, and you are treating them badly.

you guys may be right. but, i found that girls never care about me and drop me at the first more interesting pursuit. so i can only return the favor.

*sigh* seems you'll learn the hard way.

Not as awesome as you think it is. Seriously, grow up.