I've never understood the lying. I don't know how many times on a night out someone has seemed interested in trying to get me into bed and when I've said I'm not interested in one night stands they come out with, "But it won't be one". Of course it will! I'm not an idiot so don't lie to me. I'd rather them be up front and honest about it. "Yeah, it'd be a one night stand but maybe you'd enjoy yourself" - come out with that instead. The amount of men that say it though shows that most women buy it, which means they think lying is the best way to go and then women complain about being used by liars to get off.
Also, yes. Women do lie too - I'm not saying we're saints.