Sex is serious.
Nothing is worse than a somber-faced man during sex. We get it, you're concentrating, but sex should not be taken so seriously. This is adult play time, and you should be visibly enjoying yourself, and yes, even laughing. When two sweaty, naked people collide, the result is often hilarious. Body squeaking and forehead smashing will occur. You'll let out a weird moan that sounds like it came from another species. Embrace the comedic side of sex. It's healthy to laugh, and it creates an atmosphere where there are no mistakes, just good jokes.