They have remained remarkably friendly despite divorcing in 2006.
So perhaps it should come as no surprise that Charlie Sheen was seen getting up close and personal with Denise Richards.
However, the pair's amorous encounter is only for the cameras, as it occurs on the latest episode of the controversial star's TV sitcom Anger Management.
Just like old times: Charlie Sheen bedded ex-wife Denise Richards on Anger Management on Thursday
Pleased with himself: But it turns out his character has a dastardly way of getting his lady into bed
The Loaded Weapon actress played Lori, Charlie's crazy ex who had refused to sleep with him in the past. But while they finally do the deed, his character Dr. Charlie Goodson, a former minor-league baseball player who became an anger management therapist, ends up complaining to his friends it was the worst sex he ever had.
However, he soon realises anger fuels her sex drive and makes her great in bed.
And after getting her angry several times, even at one point provoking her to the point where she tips his coffee table before jumping in him, he has a pang of guilt.
Old friends: However it emerges her character Lori was the one who got away before he could bed her
Wind up merchant: He eventually discovers that making her angry turns her into a sexual tiger
Pouncing: And the manipulative anger management therapist's prodding seems to do the trick
Having his way: And Charlie will have enjoyed filming the scenes as he admits he still carries a torch for Denise
He ends up dumping her again after deciding he cannot be an anger management therapist and keep getting someone angry just to have sex with them.
Excited Charlie was obviously delighted with how the episode panned out, as he took to Twitter to promote it to his followers on Thursday.
He said: 'tune in tonight & check out my favorite ex-wife on Anger Management FX @9p She rocks. She's smoking hot.'
Fuming: The doctor's constant barbs enrage her character so much she upends Charlie's coffee table
Exhausted: The pair looked bedraggled in the scenes set after their passionate encounter
His plan worked: Charlie looks smug after using his mastery of psychology to have his wicked way
Feeling guilty: His character eventually breaks up with her again as he feels he is being unethical
He said: 'She still looks f***ing great. Do I want to [have sex with her]? Yeah! Does she? Don't know.'
The pair, who have two daughters together, were married from 2002 to 2006.
And Denise is clearly still an in demand actress, for she was spotted filming new pilot Twisted in Los Angeles on Friday.
Its a tough job but someone has to do it: A fellow was tasked with brushing down Denise's outfit while make up was applied as she filmed a TV pilot in Los Angeles on Friday
Gorgeous: Denise's long hair was perfectly highlighted with several blonde hues