On night a kid walks in, just as his parents are have sex. He runs out crying.
Then next day, his mom goes to speak to him about it. “Did you see me last night on top of daddy, bouncing up and down?” The kid nodded. “You know daddy has a big belly, well I was trying to flatten it out” The kid says “That won’t work” His mom smiled and said “Well, why not?” The kid says “Because in the afternoons, when you’re at work, I always see Francesca the maid, on her knees blowing daddy right back up”