the 2 inches added to the end of a ruler when a man measures his penis.
mines 9 inches, with the costamary 2 inch rule.
by fatassbuddabelly August 20, 2006
It means that aslong you don't put your dick 2 inches in a girls pussy you didn't have sex.
"So did you fucked that girl?"

"No, i used the 2 inch rule"
by Fetcher September 5, 2007