Whitey killin' 

Adjective: used in the same context as "fantastic," "wonderful" or "great."

"Those are some whitey killin' beats, yo!"

Whitey killin' by Anonymous August 12, 2003

killing white mice 

Inserting a tampon and the string looks like a mouses tail hanging out of her vagina.

omg, my girlfriend is such moody bitch right now, she must be killing white mice.

killing white mice by Ron Damint June 26, 2017