Heidi Klum’s boyfriend Martin Kristen is reportedly getting tired of her immature antics.

The 39-year-old German supermodel began dating her bodyguard Martin last year, following her shock split from husband Seal.

It is rumoured that although the pair are happy together, Heidi’s beau is becoming annoyed with some of her behaviour.

The star most recently embarrassed Martin at a Golden Globe Awards party in January.

“She caused a scene by dancing on top of the tables and refusing to get down,” a source told Star magazine.

“She’s impossible lately. Her behaviour isn’t winning her any friends—and it’s starting to wear thin on Martin too.”

Apparently the ambitious star has hit a midlife crisis of sorts.

An extremely successful businesswoman, Heidi is said to be desperate to maintain her empire.

“Realising that she’s getting older and doors are starting to close,” the insider said.

“She had to fight to keep her Project Runway gig [the show has only half the number of viewers it once did], so she’s feeling the pressure to keep it a success.”

Heidi filed for divorce from her husband, singer Seal, in April last year. Although she wouldn't wish divorce on anybody, the model doesn't see their break-up as "devastating".

"Did I wish for this to happen to my family? No," Heidi admitted to the US edition of Marie Claire magazine recently.

"But everyone is healthy. We're moving on with our lives. If someone got [very sick] – god forbid – that would be a real problem. It's not what I wanted. It's not what anyone wanted. But it's not a real problem."