Ever heard of telegony? Women retain the sperm cells and dna of every man they ever slept with, including casual sex partners and bathroom stall blowjobs in their brains through microchimerism. If a woman conceives a child with a another man's sperm, it affects her womb so your babies will take on some of his characteristics.

Scientists also dissected the brains of teenage girls and found while condoms lower the presence of sperm and telegony it doesn't stop it. Even if a girl has not had children, due to condoms, she retains some sperm through her saliva glands in the same way alcohol can go "straight to your head" when giving blowjobs.