box blocker
A male or female who interferes with a female's attempts to get some sexual action. Similar to a cock blocker, except it's a vagina that's being blocked from action, hence the term "box."
"I would totally have picked up that guy if you douche bags hadn't been box blocking me all night."
"I like going out with the guys to watch the game, but I never get laid those nights since they're such box blockers."
"I like going out with the guys to watch the game, but I never get laid those nights since they're such box blockers."