Boxer brings his son to weigh in, son punches opponent square in the nuts

British boxer Billy Joe Saunders and American Willie Monroe Jr are due to fight in London this weekend. 

Saunders' brought his son along for the weigh-in and everyone in the crowd thought it was pretty cute when the kid stood on the scales and had a glance down at what he weighed in at.

And then - out of nowhere - POW! He lands a punch right in Monroe Jr's ballbag.