By Jon Boon - Breaking Celebrity News Reporter

The divorce battle between Seal and Heidi Klum is about to go nuclear, Breaking Celebrity News is exclusively reporting.

The 'Kiss from a Rose' singer is furious that the Project Runway host has shacked up with bodyguard Martin Kristen, a source says, and now Seal, 49, is planning to use their relationship as leverage to get a bigger divorce settlement out of Heidi, 39, and request more time with kids - Leni, 8, Henry, 6, Johan, 5, and Lou, 2.

“Seal will make Heidi’s life a misery now that she’s confirmed she’s together with Martin,” a source revealed.

“He’s fuming that Heidi admitted she’s been dating Martin for three months. He didn’t expect her to find happiness with someone else before their divorce was officially finalized.

“It’s a real blow to his ego and he now wants more money from her in the divorce settlement – just because she’s dating somebody before the paperwork is settled. Seal will also demand that he gets more time with the kids.

“But Heidi won’t back down and isn’t prepared to give up her fortune or custody of their children without a fight.

“If she has to, she will face off against him in court. Heidi thinks he’s being incredibly petty and also doesn't think he legally has a leg to stand on,” the source concluded.

As Breaking Celebrity News previously reported, Heidi broke her silence and responded to allegations