Loose labia
When a person is overly particular and pedantic about what others say, to the point that they ruin conversations and don't let anybody have any fun.
Person 1: "Hey, has anybody seen the Mitchell and Webb show, that looks fantastic"
Person 2: "Nope, I've not heard of it, but I know of That Mitchell and Webb look and I hear its fantastic"
Person 1: "You are the biggest loose labia I've ever met Jeff"
Person 2: "Nope, I've not heard of it, but I know of That Mitchell and Webb look and I hear its fantastic"
Person 1: "You are the biggest loose labia I've ever met Jeff"