It's a totally random thing. I just happened to pass a certain house at night and heard noises so I stopped. Finally found that the noise was coming from a house. When you look in the window, you see a dude getting spanked by a woman.
And I thought the horse kicking the dude in the head thing was awesome. Had a similar thing where a dude was riding off with a woman tied to the back of his horse. I tried to stop him but he shot at me. So I killed him and ran down the horse. I take the woman off the horse and untie her and she just runs away.