Double dipping is defiantly a golden rule. You just don't do it. According to a new survey by Tostitos from PR Newswire, two out of five Americans under age 35 have double-dipped a chip.  Nearly half of men have done it . . . while only one in three women admit to it.  54% of people say that if they see someone else double-dip, they'll stay away from the dip for the rest of the party.  But 22% will use it as an excuse to double-dip themselves.