In the final episode of this innovative series about what it means to be a family in Britain today, our four families reveal their different ways of making marriage work. From breaking up to making up , from new flames to old romance - this is the couples' tale .This week Mel and Kris lead the way as they prepare to renew their vows in front of family and friends, but it's a celebration on a shoestring. Five kids, two cats, five part time jobs and a limited budget do not make for a calm week. As the ceremony looms, tensions run high. Is love enough to get them down the aisle?There are lessons to be learned from our other couples. The Chalks have been together since they were teenagers; they've weathered plenty of storms and twenty years on they're still in love. The Othen-Alexanders are experts at the challenges couples face second time round. For the Tahirs, the bone of contention is the mother-in-law.