Don't touch a little kid's hair that you don't know!

During the weigh-in for a boxing match between Billy Joe Saunders and Willie Monroe Jr., Saunders' son was allowed on stage with his dad. He was centered between the two boxers as they flexed their muscles to the crowd.

When Monroe Jr. reached down, and rubbed Saunders' son's head, he turned toward his dad's opponent, and threw a right cross into his crotchal region!

Looks like there may be a future in combat sports for little Saunders!

Billy Joe Saunders commented on the cup-check in a Tweet, but issued zero apologies.