Watermelon - Marian Keyes

It's bad enough that Claire's husband James left her the day he was at the birth of their first child - I mean, if he though it was going to upset him that much he should have just stayed at home - but to rub salt into the epistomy, he didn't even have the decency to leave her for someone skinny! He's just abandoned, leaving Claire with a newborn baby, a broken heart, two extra stone and an-er-birth canal ten times its normal size. In the absence of any better offers, Claire goes home to her family.
To her beautiful sister Helen, her soap-watching mother, her bewildered father.
And in a story that's both hilarious and bitter-sweet, Claire get better. A lot better. In fact so much better that when James slithers back into her life he's in for a bit of a surprise.