This is a sexual act that is usually between a male and a female, although it can be between any two individuals. The main goal of this sex move is full penetration. To perform this move both parties must being willing to withstand an amount of pain that would probably resemble being poked in the eye, hard. Also, they have to be somewhat athletic and decently limber. If they meet these sex regulations an amount of great pleasure can be ascertained, obviously by both parties. To perform a Jens Jackhammer one has to have access to bunk-beds that rise at least 6 feet in height, a cushy beanbag-esq chair, and a healthy sexual desire. The set-up is as such: once both parties are down to the nakedness that is the human being, traditionally, the male counterpart set himself up on the top bunk bed fully erect. The woman then gets into the spread eagle position, a most vulnerable position. Once they agree to perform this act, usually a "1, 2, 3, fuck me!" would suffice, the man launches himself off the top bunk aiming his erect penis straight into the woman's vagina. If successful, the main would have his whole erect penis inside the woman, thus experiencing full penetration and a feeling those two individuals will share the rest of their lives. This move is only recommended for those who meet the requirements above and are not faint of heart.
Jens and his lover at the time were really horny and regular missionary style was not doing it for them. So Jens suggested they do his patented move the Jens Jackhammer. Being really really horny his lover agreed and the pleasure they felt after the pain she received that is Jens cock was unbelievable and never felt before.