Top definition
1. To disprove someone or make them sad. The term is usually used as part of friendly banter or by know it alls
Brian: Jet fuel can't melt steal beams right guys *laughs hysterically*

Dave: No need to piss in your cornflakes mate, but you're not funny
by Zorkkins August 02, 2016
Get the mug
Get a Piss in your cornflakes mug for your daughter Yasemin.