But hooking up by the water isn’t all romantic splashing, steamy kisses, and trying not to capsize your giant swan floaty. There’s a lot more to it. Even though you might be getting physical with your partner while submerged, you still have to take precautions to avert STDs — and if you’re having P-in-V sex, and you want to avoid pregnancy, you'll still have to take precautions. This is surprising to some folks, who mistakenly assume that if chlorine can kill germs and even COVID-19, it can obviously kill sperm. But it’s not so simple, explains Erica Smith, M.Ed., a sexuality educator in Philadelphia, PA.
“Once sperm leaves the body of the person who ejaculates, it dries up quickly, so it's not going to swim around and impregnate someone who is swimming,” Smith says. “However, if two people have sex in the pool, and the person with sperm comes inside a vagina, you can still absolutely get pregnant. The pool isn't going to kill the sperm that goes directly into the vagina.”
The good news is, you can use hormonal birth control to help reduce the likelihood of pregnancy, and dental dams and condoms work just fine in the water (assuming there are proper chlorine levels where you’re wading — make sure you’re doing it in a pool you know is being maintained). One problem you might run into with condoms: “Water can wash away your natural lubricant, and interfere,” Smith says. That’s why she recommends using a silicone-based lube — no, not water based — when getting sexy while submerged.
It’s also worth mentioning that you shouldn’t hook up in a public pool — no need to subject unwitting and non-consenting third parties to you doing the dirty in the deep end.
In case you were curious, chlorine also can’t kill off sexually transmitted diseases. “Please don't use chlorine as STI prevention,” Smith says. “Much like sperm, the viruses and bacteria that cause STI infection won't live long independently in the water. But if you have direct skin to skin contact, or contact between bodily fluid and mucous membranes —like if someone ejaculates inside someone else — while swimming, you can still pass STIs.”
The bottom line, according to Smith: “Take the same precautions having sex in the water that you would on dry land.”