After a second date, what do you do if you are not interested?
1. you don't want to go on a date so you let them know.
2. you don't want to go on a date so you don't let them know.
Either way...you are a jerk. You either don't call them (or if you are a girl, ignore their calls), in which case you are insensitive and an idiot. Or you let them know in which case you either didn't give them a chance or you are making a big deal out of something that really isn't.
That is why second dates are so tough! It is a turning point where there is a one in four chance that each will want a third date--50/50 for guy and 50/50 for girl.
Guys, I would say just don't call them and girls, ignore the call. Some call this head games, most, just call it dating.
Let me tell you why.
If you call them up and are really nice and tell them you aren't interested but they have so many wonderful qualities, then you are showing what an amazing person you are and that, in the end, they were spot on to like you. If you ignore them and kind of a dipwad, then it gives them a reason to get over you.
Of corse, there is the risk to run of misunderstanding their motivations. Once I called a girl to pull the whole, 'I'm not interested but thanks' and you already guessed it...she wasn't even slightly interested. Made me feel like an real champ.
So remember, enjoy your first dates, because if that goes well, then it simply leads to the dreadful second...which can blossom into a wonderful third and beyond (or so i've been told...still waiting to get past the second date).