Nat (Rose Byrne) and Josh (Rafe Spall) get married after a whirlwind romance. As their first year of marriage progresses, they begin to learn that they don't seem to be very compatible. When one factors in the reappearance of Josh's previous love interest Chloe (Anna Faris) and Guy (Simon Baker), a romantically inclined client of Nat's, both of whom seem to have much more in common with the spouses, one wonders whether the marriage will survive for a year.
This romcom is, in the modern fashion, fairly rude, so don't go and see it if you are offended by smutty humour, sex, nudity or bad language. It is also, again in the modern fashion, largely powered by the humour of embarrassment (best friend Danny (Stephen Merchant) delivers a Best Man speech of excruciating embarrassment, aware but uncaring of the offence and discomfort he causes, for instance). Again, if you don't care for this sort of humour, you're not going to enjoy the film. And it's clear that a number of reviewers, both professional and other, belong firmly in that camp - nobody likes everything.
But the proof of the pudding lies in the eating. I saw this film in a fairly well attended screening with a mixed audience, mostly mature couples and not the sort of audience I would have expected this film to appeal to, except that they were all people who had experienced the difficulties which the experience of living with someone else brings with it. And that is at the heart of this film. When I wasn't laughing out loud, I was giggling almost constantly - I found this film very funny. And, from the evidence of my ears, I was not alone - there was a lot of (especially female) laughing out loud.
Spall and Faris have some funny stuff, and Byrne is also funny by virtue of playing it straight - of the 4 principals, only Simon Baker suffers from an absence of humorous material. But the secondary characters make up for this, with Merchant's crass best friend and Olivia Coleman's sour relationship counsellor being best of the bunch. There are some very funny set pieces - Baker's attempted hotel seduction, Faris' threesome, Coleman's phone diatribe - and stay through the titles in order to catch Jane Asher's final line.
I really enjoyed this and I recommend it highly (but only if you are in the mood for that sort of thing).