Persona Non Gratuitata ...

Persona non gratuitata
[per-soh-nah nohn grah-too-i-tah-tuh]
N., the person at any food or drink-related group gathering that consistently feigns ignorance and under-contributes his/her portion of the overall group tab; examples include: forgetting to include taxes, tip, soft drinks and any shared entrees, appetizers or side dishes in the final bill reckoning

This is typically a regular occurrence for the offending party and therefore an extremely tough habit to break. For fellow group diners, it is especially awkward to broach the topic of underpayment with the perpetrator (for fear of seeming petty), ... an omission which unfortunately only seems to perpetuate this odious behavior

In many cases, the underpayment is often accompanied by a calculated diversion (an unexpected phone call, a trip to the restroom, spontaneous conversation or an early departure) to avoid detection.

See also tab averse and tab jumping

Bourbon foam ...

Bourbon foam

n., the alabaster-hued compound created by the combination of the following: a) a straight whiskey distilled from a mash having 51 percent or more corn (bourbon), b) a carbonated soft drink (coke) containing an extract made from kola nuts, together with sweeteners and other flavorings and c) time.

"At halftime, the fourth-year UVA student stealthily removed his flask of Evan Williams from his sock and mixed the whiskey with his extra-large stadium Coke. Moments later, he could see that his drink had a pleasing and intoxicating layer of bourbon foam."

See also Maker's Mark, Jack Danieline and Beamsicle