When a couple is always together, but not as in cute together, as in he is always putting his hand down her shirt, and she always has her hand in one of his back pockets. This term is preferable towards girls with no chins and albino douchebags.
What the fuck? That guy and girl over there are all OVER each other! Can't they learn some class? Oh, wait, they're a Rachen? Oh then forget about it, they won't ever learn.