I was staying with my wife at friends' (2019, before covid) and she asked me to nip down in the morning and make us a cup of tea. As I was waiting for the kettle to boil, our friends' wife appeared for the same reason, but didn't expect to see me and was wearing just a large t-shirt, she has great legs and was looking just nicely dishevelled and I couldn't help getting a bit of a boner. She couldn't help noticing but we tried to ignore it and we chatted about the fun we'd had over dinner the night before and I told her about how we'd once ended up swapping with other friends after another dinner party once. She said I should've mentioned it before, but my wife isn't really into that kind of thing these days so I hadn't, anyway, her husband definitely isn't into that kind of thing, but it became apparent she'd be more adventurous, especially as she was leaning against the counter top next to me waiting for our tea to brew. I brushed against her to get the milk and she reached down and stroked my cock. I was weak - I admit - and didn't stop her, and as we were about to make the tea she stroked me hard and fast and made me cum over the kitchen floor. When she bent over to wipe the floor it became apparent that the t-shirt was the only thing she was wearing. We took our teas to our respective partners and that was it, and I am still fantasising about whether it'd be a very bad idea to finish the job once we are able to get back together after lockdown.