The term joined at the groin can also be used as an adjective to describe a couple who are sexually active.
More About Joined at the Groin
When used as an adjective, the term joined at the groin usually refers to a couple experiencing new relationship energy and thus having a lot of sex. Alternatively, it may be used to describe an established couple who are well known for their sexual exploits.
While the origin of the term joined at the groin refers to vaginal heterosexual sex between a man and a woman, lesbians, gay men, and couples of other genders and sexual preferences can also be said to be joined at the groin.