Propose to her

"You know what? Fine!" You shout, "You called my bluff!"

Kristen turns around, still smiling and very much still naked. You drop on one knee, rummage through your backpack, and pull out the ring.

"Kristen Anne Montague," you open the ring box, "will you marry me?"

"Oh John Smith," she scoffs, "of course I will!" as she bends down for a deep embrace and kiss and leads you up to the bedroom.