You Just Know

Refers to a woman (Primarily white) having sexual intercourse with an animal.

Joe:dude check out this cute chick at the stables.she really likes those horses!
John:you just know
Joe:what?

By Sydney

You Just Wouldn't Know

It's something a girl says to a guy to make him shut up.

To explain to a guy that it's something a girl does

guy:I don't get why girls are like that.
girl:you just wouldn't know

guy:You spent $100 on cds!
girl: you just wouldn't know

By Carolan

Define You Just Know Meaning