Camille Grammer was filmed visiting the former Frasier star during his stint on Broadway for the first series of the U.S. reality show in 2010, but their meeting, which came after they had not seen each other for weeks, appeared awkward to viewers.
The couple split later that year (10), and the actor has opened up about his reasons for agreeing to the Tv appearance.
In an interview with U.S. newsman Anderson Cooper, due to air in America on Wednesday (26Sep12), he says, "I was trying to pretend things were normal for the sake of letting her have that moment."
Grammer has since gone on to marry new partner Kayte Walsh, who he first met while he was still with Camille, and the star admits he wishes he had not allowed cameras to document the pre-split meeting.
He adds, "It (cameo) was just ill advised. It was the wrong decision and I should have come home from England when I first met Kayte and just said, 'Listen I've met somebody and this hasn't been working for a long time.' I regret not doing that.
"I thought I could do something nice, some parting thing and so it was very painful and uncomfortable. It was uncomfortable for Kayte, it was uncomfortable for all of us."