I imagine a Time Lord's attitude to sex a bit like this:
Imagine you're on a planet where everyone is absolutely crazy about chess. And I mean REALLY crazy about chess. Magazines are full of speculation about who's playing chess with whom. Married couples seek professional advice to improve their chess life. Some like threeway chess, some play chess in tight fitting latex suits, some play chess only with the lights out and insist that everyone else do the same. That planet's largest network is full of pictures of pretty people moving queens up and down, bloggers who discuss whether fictional character x likes chess in the first play, and every day you get hundred of e-mails telling you how to enlarge your king without side effects. Now, it's not that you don't like chess at all, every once in a while an interesting player comes along and you're tempted to get out your board, but generally? Wtf, planet?