Pair of Tongs

You balancing on one arm in a side plank. Him holding your waist. He straddles your bottom leg and inserts P in V.

Why It's Impossible: If you're not a master at side plank, or don't have the upper body strength of Madonna, your arms are going to collapse or you are going to fall on your head the minute he starts pumping. Let's be honest, he's going to forget that you are in a precarious position the minute penis hits vagina and sorry to be the bearer of bad news, but side entry doesn't always feel pleasurable.