‘Real Housewives of O.C.’ Slade Smiley — Attacked on Red Carpet for Deadbeat Dad Payments [VIDEO]

Gretchen Rossi and Slade Smiley were caught in a CRAZY scene last night when a bill collector angrily hit “em up for more than $100K in late child support Slade allegedly owes for his son … an 11-year old who”s fighting brain cancer.

The “Real Housewives of Orange County” couple had just stepped off a red carpet in Hollywood last night when the bill collector jumped out and shouted at Slade, “Pay your child support! Your son has cancer.”

As our sources reported, Slade owes a major chunk o” cash to his ex-gf Michelle Arroyo. Their son Grayson was diagnosed with brain cancer at age 6 and has had 11 surgeries.

In the video, the collector repeatedly says Slade owes $160,000 in back child support — but Michelle tells our sources the number was around $130,000 … until she agreed to reduce it to $95,000 in a recent court hearing.  

She claims Slade is currently paying her $775 per month. We called Slade”s rep for comment … but haven”t heard back yet.