If the controversy sparked by their decision to take three-month-old baby Faith to the bash wasn't enough, Kayte appeared to dress up as Kelsey's ex-wife... yes, for Halloween.
Which witch? Kelsey Grammer (dressed as a vampire) says his wife Kayte Walsh attended the Playboy Mansion's Halloween party as a witch despite her resembling a parody of his Beverly Hills ex-housewife
Walsh posed with her husband - who she met when she worked as an air steward and he was still married - in a glamorous blonde wig, a fancy lace dress gown and a nose plaster.
Beverly Hills bombshell: Kayte looked nothing like Camille Grammer in her Halloween costume, she was dressed as 'a witch'
The mother of his children Mason and Jude, who he was married to for 14 years, also admits to 'having a crock full of Botox' and is widely suspected of having had surgery on her nose.
Though she has never admitted to any such work, her appearance is certainly pilloried as artificial in some quarters.
Even the wig alone draws too much of a comparison to Camille, and surely they both must've have realised this.
But not according to Kelsey, who told the Mail Online that Kayte was at the party dressed as a... witch.
He said in a statement: 'Kayte dressed as a witch (her hat was missing as she had removed it because her wig was itching and it was hot) - I threw together an uninspired Dracula.'
His representative added: 'She looks nothing like Camille.'
So that clears that up then, or does it? You decide.
Certainly, it would be ridiculous to dress up as the woman you replaced for Halloween.
But then despite the fact the Frasier alum left Camille for Kayte, he hasn't been too charitable towards his former life partner.
He did admit that he should have told Camille about meeting Kayte before filming scenes for her Bravo show, The Real Housewives of Beverly Hills, that soon became dramatic.
Grammer insisted he wanted the show to be a 'parting gift' for his outgoing wife, but he insisted he just kissed Kayte initially.
Keen to clear up any suggestion that the couple spent the night together before his split from Camille, he ended up telling Conon he'd been trapped in a sexless marriage.
Different look: Kayte favours more natural chic, here with Kesley as he shows off his Golden Globe in January
Still happy, then: Kelsey claims he was in a sexless marriage for a decade, here he arrives at an event with Camille in 2006
'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.
Camille, 44, has said she bears no ill will towards her four times married ex, but wishes he'd stop his negativity tour.