Update: After the last report that Robert De Niro was in talks to sign on, things have advanced to the point where he's officially aboard, according to The Hollywood Reporter. He'll be the one member of the group who A) dislikes partying and B) has an issue with Douglas over the romantic problems in the past.

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OAPs-on-a-bachelor-party-bender comedy Last Vegas has, like many complicated stag dos, taken a while to organise. Jack Nicholson was flirting with one of the lead roles for ages, but never seemed to commit. Now Michael Douglas is packing his bags for a wild night in Sin City.

The film finds a notorious playboy (Douglas) finally deciding to settle down and get hitched, albeit to a woman half his age. He decides to throw a stag night in Vegas and invites his three childhood best friends to come and party with him.

But all doesn’t go exactly to plan on the night when two of them dig up old tensions related to the woman they both loved back when they were teenagers. Sounds more Grumpy Old Men than The Hangover, but given how popular the latter is these days, who knows how the script has been tweaked to up the madcap comedy ante.

Jon Turteltaub is calling the shots (both cinematic and jello), working from a script by Crazy, Stupid, Love’s Dan Fogelman that has since seen re-writes by Adam Brooks and Alan Yang. The cameras are set to start cranking this September, once Douglas is finished playing Liberace for Steven Soderbergh.