Definitions by Paddy McMurphy

yellow card 

Expression meaning that a girls nipples are visible through her shirt. Deriving from the automatic yellow card given to soccer players if they slide tackle with their studs ( cleats ) showing.

Me : Dude it's cold.
You : Wow look at that girls nips.
Me : Yellow card ! Studs showing.

yellow card by Paddy McMurphy October 22, 2007