Sometimes when I walk past girls (usually aged 18-20ish) I'll try and make eye contact, and they'll look at me quickly then look away and will make the facial expression where they pull their lips in, as if they were making an 'ummm' sound, if that makes sense? Does this mean anything inparticular or am I being pedantic?

Could be wrong but it sounds like a polite/forced smile. Could it be that?

To keep from vomiting?

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They call me the cat whisperer, cause I know exactly what the pussy needs.

Bollocks, I was afraid of that. I'm one of those guys that some women think I'm gorgeous and others think I'm repulsive. Didn't think I made girls want to puke though

LOL he's fucking with you man.

Maybe it's something to do with YOUR facial expression that is making them make this facial expression that you are talking about. This is something that alot of guys don't realize... but your facial expressions tell alot about what you are saying. (even if you aren't saying anything) If your face looks nervous, she is going to feel nervous and give off a nervous facial expression herself.... or call you a creep lol

this might be of some help
http://www.boards.ie/vbulletin/showthre ... 2057026670

For the record I do smile when I make eye contact. I think it might just be a nervous/shy sort of thing. For example one of the girls who does it, I have on facebook (she added me) and will be perfectly happy to like things, comment on things etc. Surely someone who thought I was hideous wouldn't do that? Girls won't pay any attention whatsoever to ugly guys.

You're ugly bro, deal with it. I'm joking.

It could just be the way you're looking at them. Maybe you stare too hard and too long or you're slouched over while you walk but still look and smile at them. Your whole body language should be saying "I'm confident". If you're not conveying that people will be put off by a stranger looking at them.

Head up, shoulders up, smile(Work on it in the mirror and your grin! Everyone and I mean EVERYONE does this for pictures and general purpose!!) and walk proud. Wearing clothes you feel comfortable and confident in is like half the battle.