When ya mess with bull, ya get the horns ... right in the balls.
That's the lesson decorated matador Paco Urena learned when he stepped into the Vista Alegre bullfighting arena this week at the Semana Grande Fair in Bilbao, Spain ... where he ended up with a crotch full of horn.
OLE!!!!!!
Unclear how badly Urena was injured in the incident -- but it seems like his man-junk survived because there are photos showing Paco proudly showing off the bull's ears as trophies.
As you probably know .