Four men, one of whom is about to be hitched, go on a stag outing to Las Vegas.

However, when they consume what they think is a relatively harmless drug they find it obliterates their memories.

They wake up the next morning in a $4,000 hotel suite with a tiger in the bathroom, a baby in the closet, a bubble bath full of inflatable sex toys and a smouldering sofa. They’ve also lost the bridegroom (Justin Bartha).

We gradually find out what happened as they try to find him.

I won’t tell you too much, but you should know that Mike Tyson is the owner of the tiger and contributes an amiable cameo during which he sings a song and only delivers one punch.

Todd Phillips’s film is funny, sharply written and well acted by Bartha, Bradley Cooper, Ed Helms and Zach Galifianakis, but in the end it runs out of steam.

Its subject is men who revert to adolescence when given half a chance but it hasn’t the guts to criticise these terrible dorks and presents the few women in its cast, like the silly, golden-hearted prostitute (Heather Graham) and the ball-breaking girlfriend (Rachael Harris), as equally laughable.

Film Trailers by Filmtrailer.com

Even so, this is an above par effort, excellently played and just naughty enough to be thought daring as well as amusingly spiteful about the arrested development of