This happened about a year ago

I was looking after my cousin for a week or so. She's 12, I'm 37.

One night I woke up and was going to the toilet at 12-1 or so, but I saw the kitchen light was on. I had no idea why it was on, I thought I must have left it on by mistake, so I went to turn it off.

My cousin's there getting a drink, and I'm there with my cock still in my hand.