Many funny things come to mind....
Once, when I was enjoying some fabulous doggy with a young WG who had a tiny waist, a bubble butt and a small, tight pussy that sort of protruded past her buttocks when she had her face buried in the pillow. As I held her with both hands around her waist, I was looking down, mesmerised at the sight of my glistening (covered) cock going in and out of her (I defy any man to NOT be mesmerised by that....) and I could feel the sap start to rise. Seconds away from the point of no return, her fanny erupted with a big pocket of escaping gas, and she said 'Oops!' and began giggling like a loony. It started me off laughing like hell too, and at this point my right knee slipped off the edge of her bed and I took a header onto the chair with my clothes on it a couple of feet away. I ended up pulling her off with me, and after hitting the chair, I smacked face-first into her bedside table. As I did that, I stuck my arm out, cleared everything off it - lamp, water glass, massage oil, plus my own stuff and hit my head. I ended up with a bleeding dent in the middle of my forehead, still laughing as she hit the floor like a sack of tatties as well! She was very sweet about it, despite the carnage, and I ended up way over time lying back still holding my head and enjoying a first-class BJ!