Britney Spears has put ex-hubby Kevin Federline on a diet because he’s gained a whopping 85 pounds. The 5-foot-10 former backup dancer, who weighed 150 pounds when they married in 2004, now tips the scales at about 235 pounds.

Back when they were married, Kevin used to chide Britney about her weight, but now the dinner table has turned. These days, it is Britney who is making the jokes – calling him ‘K-Fatter-line’ and other names.

“She’ll ask him, ‘When is the baby due?’” revealed a source.

“Britney called him ‘a fat housewife,’” said the source. “[Kevin] says he’s gained weight because he is happy and content, but Britney says he is just fat and lazy. Britney insisted he go on a diet and stop showing their kids it’s OK to be fat and sloppy.”

Kevin says he doesn’t have to worry about his looks,” said the source, “because women still love him.”