Wyatt Koch — the son of billionaire Bill Koch — is suing his ex-fiancée to get back an 8.24-carat ring after she broke off their engagement, according to court documents. Wyatt’s lawyers claim that he purchased the pricey Oscar Heyman cushion-cut diamond with two tapered baguette diamonds for $180,000 in March for a Tallahassee lassie named Ivie Gabrielle Slocumb.

But come May — after she allegedly “broke off” the engagement — Slocumb kept the rock. Wyatt’s lawyers say the ring’s now worth $250,000, and Wyatt also wants $15,000 in damages.

According to court documents filed in Florida circuit court, Wyatt — known in Palm Beach as the flame-haired, flamboyantly attired CEO of his own Palm Beach fashion line, Wyatt Ingraham — has “demanded the return of the ring . . . on multiple occasions” and says that the would-be bride “received the ring as a conditional gift. She refuses to return it despite proper demand and the condition not being fulfilled.”

A receipt filed with the court reflects that he also splashed out on a $7,750 “platinum diamond pendant” with 56 round diamonds, that’s not part of the suit.

The engagement — as well as Slocumb — are otherwise a bit of a mystery.

Slocumb has 20 days to respond to the suit, according to a summons dated Dec. 13. Attorneys for Koch, and Slocumb, did not get back to us.

In an Instagram video posted earlier this year for his clothing line that specializes in shirts with out-there patterns and colors, Wyatt explains, “My father said to me, ‘Wyatt, you can do whatever you want to in life. Just make sure you do it well and do it with passion.’ ”

The billionaire scion adds in the video, “Everyday I go to the office, I enjoy creating the clothes. ‘Be bold’ means to me — be authentic, be real, be yourself, be confident and always be a gentleman — but still have that tenacity that no one can take away from you. I want my shirts to be able to worn in the boardroom or in the discoteca or a nightclub — or on a yacht. I really wanted to create something that’s fun, outside the box, cool, trendy, yet really bold and interesting.”