I know it's her. Sometimes you can just tell when the doorbell rings. Mike knows it's her, too, which is why he doesn't answer the door. He likes me to do it. Suffer the humiliation of me letting her in. Inviting her in.

I answer the door. It is her.

'Hi, Mrs. Jones!'

My children were right behind me. With my head swimming, I didn't even know they were there. They beam up at the woman at the door and she steps in and bends down to them.

'How are you guys? Did you have fun at school today?'

They nod the affirmative and scampers upstairs to their room. I shut the door behind her and we stand together, alone in the hall for a moment.

'Hi, Amanda.'

'Hi,' her smile is friendly, not in the least bit sadistic. 'Is Mike in his room?'

I tell her that he is, and without another word she slips into the room where my husband is waiting for her, and closes the door. I ruminate for a few seconds on whether I would still be stood here, in this exact spot, with the same set of circumstances unfolding, had he never met Lucas. Then I think back to how long ago it was that I accepted Mike cheating on me, and I realize the answer is probably yes.....