I was at a bbq on Sunday, it was at a pub in a small town where I went to a wedding the day before. There was a few of us sitting around a picnic table, and talking about interesting places that people had previously had sex. One of the couples told their story:
They were staying at a house belonging to friends of a friend. It was a kitset house, so the walls were really thin. C & K got a bit horny and decided to have sex, but because the walls were so thin decided to get on the floor, because the bed squeaked. C was doing K doggy, and when he withdrew his cum shot over the top of K and hit the wall in front of them. That in itself wasn't so bad, it was the fact that they suddenly realised that his cum was stripping the paint off the wall as it slid down the wall!! They said they couldn't get out of the house fast enough after that!