Brash WBO middleweight champion Billy Joe Saunders has never been one to censor his comments or avoid reaching below the belt to get his point across and apparently it runs in the family. 

Saunders (24-0, 12 KOs), who defends his 160-pound title on Saturday in London against former world title challenger Willie Monroe Jr. (21-2, 6 KOs), made headlines along with his young son, Stevie Saunders, at the weigh-in one day earlier. 

As Saunders and Monroe posed on the stage after weighing in, the younger Saunders stepped between the two fighters. In a gesture of goodwill, Monroe put his hand on the child's head, but with a smile on his face, the younger Saunders surprisingly punched Monroe in the groin and attempted to kick him in the leg until the two were separated. 

Saunders, 28, who will be making the second defense of the title he won in 2015 by outpointing Andy Lee, stood up for the actions on his son after the weigh-in on social media. 

A native of Hertfordshire, England, Saunders possesses the only one of four recognized middleweight titles not currently owned by Gennady Golovkin, who will face Canelo Alvarez in Saturday's pay-per-view bout. Monroe, 30, of Rochester, New York, was knocked out by Golovkin in their 2015 title fight. 

Saunders-Monroe will take place at Copper Box Arena in London's Hackney Wick section. The bout will be streamed live on Banner Promotions' YouTube page (5:30 p.m. ET).