Sex Cave

The state (often in the early stage/s of a relationship) of being in a state of constant sexual intercourse.

This state can last for weeks at a time and, can cause serious damage to your friendships.

"Where've you been for the last six weeks?"
"Since I started dating Joe, we've been in the sex cave non-stop."

"You coming to the pub next week?"
"Sorry bro, I'll be in the sex cave."