When Kelsey Grammer appeared on “Conan” recently, he slipped in a joke about sex that his ex-wife doesn’t find funny at all.

It began as Grammer defending his new wife’s honor after reading several blurbs about how they’d met–some online commenters were asserting that the two had a one-night-stand that blossomed into something more–and wanting to clear the air.

“I did want to clear this up…it said something about how Kate and I had met and hooked up in London and that she’d spent the night with me, you know, a one-nighter. That’s not true. We kissed that night….we didn’t do much more than kiss, actually, for several months.”

“I would think that would be difficult,” Conan said. “You meet someone, there’s obviously passion there…”

“Oh, for a guy who hadn’t had sex for a decade it wasn’t that hard,” Grammer said with a laugh.

Apparently, Camille is rather upset that her ex would say such a thing on national television, and a “source” close to her says that while the couple did refrain from having sex during their marriage, it was only after Grammer had a heart attack in 2008 and they were forced to “diminish their sexual activity”.