If you sleeping 300D fabric Wholesalers with an ugly guy, then you better make sure you're on the pill if you don't want him to get your pregnant. A new study, set out by the University of Oxford and University College London, shows that ugly men produce more sperm during sex. The flipside: The hottie you shagged last night probably didn't knock you up.

Here's why: Attractive men are more confident that they'll be sought after and will have multiple opportunities to sow their oats. Therefore, to save his sperm for all the play he's going to get, he only emits a small amount per potential mating. Long term, he'll allocate the same amount of sperm as an ugly man will, but it'll be spread out over a longer period of time, decreasing the chance of impregnation each individual time.

Unattractive men, according to this study, have sex as a survival mechanism. Unlucky with their appearance, they may also be unlucky in love-maybe this one mating opportunity that they've got presented before them will be their last. If that's the case, then they better spurt out as much semen as possible to ensure that their family line lives on. They may attract fewer mates over time, but they value each one more than the attractive guys do.

I keep saying "men" or "guys", but in reality, this theory hasn't been tested on humans, just on chickens and birds, so I should really be saying "males".

In any case, you don't want to rely too heavily on this new science. If I were you I'd stay on your birth control pills, even if your new partner is Brad Pitt.