Claiming one's spot on a couch by rubbing ones head back and forth on the occupants body. Ususlly used by homosexuals that are sooo gay!

Bizarre sexual gratification method involving making an incision in your partners thigh with a scalpel and making love to the wound

One step up from Nesting. This can include hardcore making out. This act is always done in public areas making everyone very uncomfortable.
Burrowing can lead to babies.