why do guys flirt with girls if they are already with someone?

Men like to see if they still got it.......lol Women do it to, Its not that they are looking to cheat it's an ego thing.

Guys are no different than girls. Regardless of the fact that you may be in a relationship with someone, or be in love with them, flirting is nothing more than a reassurance that others still find you attractive. It is usually harmless and just makes people feel good. However, if flirting becomes more than that then we're in a whole new ballgame. Donna

they do it to see if they could have you if they were single, its an ego thing. they like to be reassured that other girls would like them besides their girlfriends

y not, it's just 4 fun, he's still with u that's all that should matter