That is a fun idea, and that had crossed my mind. A few random ideas:
1. Waitress puts the check in his mouth and puts her foot on his head in a victory pose.
2. With the waitress's consent, the woman makes him kiss the waitresses feet or lick her shoes.- here the waitress being more passive would prevent loss of employment and/or liability concerns the cafe owners would have.
I have more but there are probably even better ones in your imagination.