I don't feel the need to wait in a casual relationship, but when things are working well I tend to hold it off to make sure it's because we like each other, not because the guy only wants to bang me! I've only had two serious relationships, and in both we waited only 2 to 3 months, but I've heard of other people holding off way longer.
So, ladies & gents, what's the longest you've waited and why?