InTouch obtained the court filing, which shows McDermott hasn't paid child support since March 2015 for his 16-year-old son, Jack, who he shares with Eustace.
A source tells the outlet, "He's a deadbeat dad. He never thought he'd be served."
McDermott has 30 days to pay up, otherwise further legal action will be taken.
But if reports of McDermott and his current wife Tori Spelling's financial situation are correct, then it's likely that McDermott isn't a deadbeat dad so much as one in some serious financial trouble.
Life & Style reported back in mid-July that Spelling and McDermott downsized their living situation for the second time. The True Tori stars have apparently blown through $18 million
Still, Eustace doesn't seem to be buying the reports.
"He and Tori Spelling are living in a beautiful, gated community and throwing lavish $10,000 birthday parties for their children," she told Life & Style, "but Dean still insists he had no money for a cup of coffee."
Dean is a deadbeat dad and has no shame," Eustace added.
The couple did, after all, just throw their daughter a lavish panda-themed birthday party with seemingly no expense spared.
Every detail at Stella's panda pool party was perfect! Special thx 2 @sugarpearlbakery 4 the amazing panda cake, @backdropinabox 4 that gorgeous pink & black flower backdrop and @babyfaceboutique 4 making custom panda outfits for the whole family! Head to my blog ToriSpelling.com 2 see the rest of the pics xoxo
But in Spelling's defense, it could be that a lot of the supplies were donated as promotional items, since Spelling definitely tags all of the contributors for the bash.
Still, Spelling has not been shy about explaining her loose spending habits.
She wrote in her 2013 book The High Life, "It's no mystery why I have money problems. I grew up rich beyond anyone's dream. I never knew anything else. Even when I try to embrace a simpler lifestyle, I can't seem to let go of my expensive tastes. And then there's my shopping problem. I've bought ridiculous amounts of stuff for the kids: clothing, toys, crafts."
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