Bowner Killer
A "bowner killer" is when you hear something awful or disgusting. Such as when a girl talks about her period, or if you see this incredibly ugly girl. It is also directly known as something that makes you have the opossite of a bowner..
It is also known as BK.
Girl: Today I was bleeding like a waterfall!
Boy: Dude! that was a total BK!(bowner killer)