Mollie and James are together and raising a family, which now consists of an older Mikey and his baby sister, Julie. Tension between the siblings arises, and as well with Mollie and James when Mollie's brother Stuart moves in. Mikey is also learning how to use the toilet for the first time.

Mollie is a single working mother who's out to find the perfect father for her child. Her baby, Mikey, prefers James, a cab driver turned babysitter who has what it takes to make them both happy. But Mollie won't even consider James. It's going to take all the tricks a baby can think of to bring them together before it's too late.

When high-powered executive Samantha LeBon hatches a scheme to spend a romantic Christmas with her new employee – the unsuspecting, blithesome James – his wife, their kids and their two dogs, Rocks and Daphne, must rescue him before he makes a terrible mistake.