You know your grandparents are doing it when...

10. A pair of edible Depends is found on bedroom floor.

9. Lately, at night, they put their teeth in the same glass.

8. Grandpa grabs his crotch and complains loudly of "denture-burn".

7. Granny is found cuffed to her walker.

6. Not only do you hear the bed squeaking, but also joints.

5. Grandma regularly looks at Grandpa's crotch and claps twice.

4. Your "Grandma" is Anna Nicole Smith.

3. You've just seen the photos in the "Beaver Hunt" section of the May issue of Hustler.

2. Grandmother starts baking Viagra-chip cookies.

1. Their Craftmatic adjustable bed is set for "doggy style".