Dean McDermott, who was famously caught cheating on wife Tori Spelling, hasn't only been pulling bad dad behavior with his current family.
RadarOnline.com can reveal that the father of Spelling's four young children has neglected the teen son he left behind when he divorced ex-wife Mary Joe Eustace, 53, nearly 10 years ago— and owes thousands in child support!
"Dean hasn't been paying Mary Jo what he owes," an insider tells RadarOnline.com of the father to Jack, 16. "She's really upset and wants him to pay up!"
Spelling, 42, and McDermott, 48, have notoriously dealt with financial woes.
The actress' ABC Family series with fellow Beverly Hills, 90210 alum Jennie Garth, Mystery Girls, was canceled last year after just one season. Meanwhile, McDermott quit his gig as the host of Chopped: Canada in March.
On Father's Day, the couple held a huge garage sale to pull in some extra cash.
McDermott and Eustace have been at war for years. He infamously cheated on the Canadian actress with Spelling while filming a TV movie together in 2005, then left her for his costar.