Eva looked out the attic window of their charming guest house and watched the sun rise. She thought she might be sick. Splayed on the lawn below was Frank, apparently out cold.

Her husband snored in the bed behind her. She loved Shay, of course she did, but right now the only person she wanted to think about was Conor. She didn't want to think about Bea or Lizzie or what Lizzie might have got up to with Shay.

Frank's 48th birthday had given the three couples an excuse for a much needed night away from children, nagging bills and ailing parents.

The drink flowed, life in Dublin with all its stress felt a long way away. When Frank proposed they swap partners, it felt deliciously, irresistibly reckless. One night.

No obligations. No expectations. All the women had to do was text a man of their choice.

The only rule? No falling in love.

It was a night that some of them couldn't remember.

And others couldn't forget.