A rule that states a penis can touch anything for up to five seconds before the object is considered molested.
Husband: (poking dick against cosmetic mirror)
Husband: Look honey! It's kissing its reflection.
Wife: Urg! Stop molesting my mirror!
Husband: I'm not. 5-second rule! See. Smooch, one second. Smooch, one second. Smooch, one second...
Wife: (leaves to buy a new mirror)