ponzi beer
a beer you buy for another person on a third party's tab, usually with said party having no knowledge of the action.
Pat: Aw man, I totally hooked with that girl last night after her I bought that beer for her.
Kevin: Pat, you turd. You charged that beer to my tab. I thought I told you to stop with the ponzi beers.
Kevin: Pat, you turd. You charged that beer to my tab. I thought I told you to stop with the ponzi beers.