That girls only try to get me when i'm already in a relationship?

I think so. There certainly is an allure to wanting something that you know you can not have.

One of the differences between men and women. Women don't want men who appear desperate and undateable (wearing a wedding ring genuinely does make a man more attractive to a woman), whereas men do sometimes want women who are desperate and undateable.

It comes from women and men wanting different things. Women want a long-term, decent provider, someone who other women have decided they also want. Men (some men, not all) want an easy mark. Morality aside, there's a part of this that is programmed into us as genders.

Women are just that way.

You could take advantage of this:
If you want to get a girl, Introduce her to your female friend with whom you've secretly arranged to act OVERLY friendly with you. While you share your attention between the two girls. Her natural instinct to win against your friend will make her want you and try to get you for herself.

You're just invoking jealousy in them which they will act upon if they think they have a chance.

I apologise to any girls that may read this as it may seem like a dirty trick, but if you do run into a guy doing this, at least you know he wants you. WHAT he wants from you is questionable though.

Everyone wants things they can't have!!!!

That's normal.

When you're with someone - or if you aren't in a dating mood - it often gives you a look of confidence, which is attractive.

On the flip side, if you're actively looking it may make you look more desperate, which isn't attractive.

Men are the same with me >< The second I'm in a relationship I get all this attention then when the relationships over all the other guys just dissapear!
Think it's just another thing to people do too make life hard ! Idiots. Haha x