In case you don't know what it is, here's the definition: [quote]Favorite behavior of crude diners. Involves dipping your crudite or corn chip into a sauce, taking a bite from the veggie or chip, and then re-dipping the half digested item back into the sauce  Made famous on Seinfeld some years back. Sign at country fair food stall: "DO NOT DOUBLE DIP!"[/quote] Source: Urban Dictionary