Supermans (or back extensions)
You can even split this into 2 10 minute workouts if you want. :)
Some other helpful hints to get through these next few days without putting on any extra weight:
1. Fill up on your healthier foods first save desert for last
2. Drink plenty of water, this will help keep you full
3. Keep your diet clean and allow one or two bad meals
4. Get some type of activity in daily
5. Don't stress!!
Enjoy your Holidays!!