The old extreme hip thrust manoeuvre that won’t be for everyone
We are told the technical term for this a kipping incline sit-up, but to the average Joe it could well be called the fish-out-of-water routine.
At the 0:30 second mark you see this gym enthusiast really take off with his intense crossfit exercise.
A few commenters have suggested that it is all to please the woman in his life, and you just thrust that he knows what he is doing, or he could easily put his back out.