Semen.

I hate semen.

Seriously. When I'm done with sex, I do this awesome gravity-defying thing to avoid getting it on my sheets. I mean, who wants to sleep on the wet spot? It's uncomfortable. Despite my avoidance, it always squishes out and runs down the inside of my thigh by the time I've darted to the bathroom after my amazing post-coital acrobatic feats of agility and grace. Sometimes it even makes an awesome not-quite-queef-but-definitely-fart-like noise as it seeps out. This is why I like being on top. When I'm done, I take the penis out of me and let the semen drip into Mr. Vixen (who is none-too-pleased, but puts up with it), at which point he grabs the cum towel from beside the bedside table. Unless he's left it next to his computer.

Life is much easier this way.