After twenty-eight years of shirking responsibility Duffy's finally realising that he can't extend his adolescence forever. His low-paid temping job is threatening permanency. His gradually receding hairline is depressing him greatly. And if that's not enough his long-suffering girlfriend, Mel, wants to get engaged.
Trips to IKEA, dinner parties with married couples and talk of babies, however, are giving Duffy cold feet. He doesn't have many worldly goods to share - apart from the remote control for his TV, the beers in the fridge and his record collection - but can he really put his hand on his heart and say "I do"? He knows Mel's the one for him, so why is it he'd feel happier swapping "Till death us do part" for "Renewable on a four year basis"?
But the choice is: all or nothing.
So after a lifetime as Mr Irresponsible does Duffy have what it takes to become Mr Commitment?