So, you’ve just made sweet, sweet love to your woman, and as you both lie in bed, basking in post-coital bliss, you think to yourself: “I’d like to eat something and then do that again.” But just as you’re about to hoist yourself out of bed to make a trip to the kitchen, she wriggles up to you, flings her arm across your chest and settles in for a serious cuddle session. Now, you really want to do it again.

Sound familiar? Well, that’s because it is. This after-sex scenario is how it plays out for most couples time and time again. Scientists believe it’s because there are evolutionary forces at work; however, as it always seems to be the case, the evolutionary forces driving men are totally different than the evolutionary forces driving women. According to a new study, Sex Differences in Post-Coital Behaviors in Long- and Short-Term Mating: An Evolutionary Perspective, which will appear in an upcoming issue of The Journal of Sex Research, women want to cuddle after sex and men want to engage in activities that are “extrinsically rewarding”–i.e. eating, smoking and drinking–or that might lead to another round of bumping uglies, like asking your bedmate for a quick shoulder-rub. In other words, men are hardwired to be horny and constantly on the prowl for sex, while women are hardwired to constantly be on the prowl for a suitable partner and baby-daddy—speaking from a strictly evolutionary perspective, of course.

The study also revealed that short-term partners are far more likely to hop in the shower immediately after sex. The researchers hypothesized that the evolutionary reason for this behavior is that women are thinking, “Crap! This relationship isn’t serious yet—I’ve got to get this dude’s sperm out of me stat!” As lovely and romantic as that theory is, we’re thinking that women are more likely thinking, “Crap! I need to freshen up and make sure I still look and smell good.” In fact, we actually asked several women if they feel a desperate need to “wash that semen right out of their hair,” after having sex with a relatively new partner and they all said, yes, but only because they wanted to feel sexy and, well, clean.