Someone somewhere is going to describe this as "a very British film", and not just because it begins with a funeral. It's not clear who the "lawless heart" belongs to, with nobody coming off particularly lightly in the fidelity stakes, whether young, old, gay or straight - except perhaps the understated character of the one older woman, who attempts to protect her brother's young partner after the former dies.
It's a courageous task to portray an entire complement of characters with little or no sense of direction, and in fact one or two peripheral figures (the children, the potential adulterous lovers) never do get coloured in, but the split narrative technique - retelling a segment three times from different perspectives, so that multiple layers of meaning substitute for one concrete version of events - offers so many possible avenues that it easily holds your attention for an hour and a half whilst respecting your ability (and freedom) to think for yourself. At first the relationships between the cast are hard to keep track of, but are allowed to emerge from their interactions during the course of the film in a way that seems much more natural than starting out fully aware of the family tree.
The multi-perspective structure is well used to show how subjective our perceptions of other people can be - Tim, returned from travelling after running out of money, initially seems to be an objectionable chancer exploiting a stranger until the fate of his own emotional life is revealed. The only casualty is the character of Charlie who, within a short space of time, seen through the eyes of the same character - the recently bereaved Nick - shifts from annoying hanger-on to quirky waitress to big-eyed slighted woman before finally skipping out of the car with a throwaway line, never to return. As a key player in one of the most intriguing emotional scenarios in the film (gay man loses partner, seeks solace in young woman, finds moral confusion) she could have done with more of a life of her own.
In general, though, it's a witty and engaging film which leaves the watcher plenty of room to move about in: it feels as though the credits could roll either sooner or later without compromising its integrity, but doesn't feel unresolved so much as untidy in the way that real life actually tends to be. Small individual pockets of each character's life are explored without the underlying emotional causes reaching some unlikely simultaneous resolution: mid-life crisis candidate Dan may well yet have his idealised "fling", but all the ideas are already laid out completely in his vague wonderings on camera. Like "Y Tu Mamá También", "Lawless Heart" is not afraid to let its characters wander off unsupervised. That, and the restrained storytelling which refuses to overreach itself and make grand statements about human relationships, makes it an unqualified recommendation.