18 When a man has sexual relations with a woman and there is an emission of semen, both of them must bathe with water, and they will be unclean till evening.

Read Leviticus 15:18 Using Other Translations

The woman also with whom man shall lie with seed of copulation, they shall both bathe themselves in water, and be unclean until the even.
If a man lies with a woman and has an emission of semen, both of them shall bathe themselves in water and be unclean until the evening.
After a man and a woman have sexual intercourse, they must each bathe in water, and they will remain unclean until the next evening.