Best Answer - Chosen by Asker Few women know this, but semen is actually automatically ejected from your body within the hour after sex. Your body purposefully gets rid of most of it very quickly no matter what you do. If you have an orgasm, the semen is actually pushed out even faster by the muscle spasms. Now, a lot of people will say, "What a second-- I've read about how it's better for conception if the woman orgasms!" Well, that's true. The whole point, though, is that the majority of sperm that make it through the cervix and into your reproductive tract do so within the first few minutes after sex. After that, your body eliminates the rest of the semen no matter what. To be crass, just think about how semen will stay sticky/slimy without ever being absorbed. This is where the "wet spot" in bed comes from, because your body doesn't want to let the semen hang around forever. Besides all that, your vagina is hermetically sealed against letting water in. If you sit in the bath or go swimming after sex, no water is going to get inside your vagina unless you purposely took a baster and squirted it in there. (Why would anyone do that?) Washing the outside of your vagina doesn't get water INSIDE your vagina, either. Point being, it just flat-out doesn't matter. There's even a recommendation out there that couples facing low-sperm count should have the women lie for half an hour