(Technical hat on) Some foods contain amino-acids that don't get broken down properly in the digestive system. Asparagus and broccoli are two; you can smell them when you pee, and to a lesser extent they can also influence the flavour of cum.

Other foods like garlic and onions can give it a bitter flavour. I'm told coffee does the same, but nothing comes between me and my first mug of the morning.

I have friends who say they can tell the difference between a meat-eater and a vegetarian by the flavour of their cum (and they prefer veggies). And there's also the story that drinking pineapple juice can improve the flavour of your cum as well, though I don't like pineapple juice enough to experiment. Anyone out there got any personal experience they can tell us about?