My mum and my step father were visiting over the weekend, but staying elsewhere. One evening there was just me at home. Mum asks if I mind if they have a bath, as the place they are staying only has showers. I say no of course, and direct step father upstairs, as mum is kindly washing up for me. I go outside to get the washing in and they've both vanished when I come back in. I take the washing upstairs to put it away to hear talking coming from the bathroom, and basically they've gone off to have a bath together.
They've been married about 6 years, so he's definitely not a father to me. I was totally freaked out and quite cross that they did this in my house with me alone there (we actually have 2 baths in separate rooms so they could have had one each!).
Go on, do your worst, AIBU to find this all really icky?
For the record, I did not say anything at all about it, I went downstairs and watched TV with the door shut.