Vomit on my shoes!

This happened last month at a Phish show. We're rockin' out -- when all of sudden I hear this splooshy sound from my right. Turns out the kid behind us chundered all over Anat's brand new kicks. She's sitting there looking at her shoes, whiping the collateral damage off of her ankles, looking in disgust at the kid. Then the salvation: his girlfriend taps her on the back. She turns to see what this girl could possibly be saying and ....... "don't worry (points to the puddle) it was all beer -- no chunks!"

What is it about McDonald's 2 1/4lbers for $2.50 that makes my stomach feel not-so-right?