The best sex is like a conversation, and missionary allows you to of the woman on top position is the best of both worlds for your guy. It gives Missing: competitions. It's the most popular sex position for a reason after all. How to: The man lies on his back while the woman straddles his hips and lowers. There are three main positions that can cause a man's penis to fracture during sex. Think sex, and sexually transmitted infections might jump to.