I am not suggesting that this way of riding a bike should be tried by everybody, but it happens to be a real picture of Rollie Free, who broke the US national motorcycle speed limit in 1948 on the Bonneville Salt Flats riding a Vincent Black Lightning. Free had made average speeds of 148.6 mph (239.1 kph) during test runs and decided to reduce drag by lying flat along the bike in the place where the saddle should have been, as well as stripping down to his bathing trunks and, apparently, sandals. He kept some kind of crash helmet on though (or is it a bathing cap?). This got him up to an average of 150.3 mph (241.9 kph) over the mile run. To see where he was going, Free followed a black stripe painted on the salt. In 1950 he went even faster, averaging 156.58, but he abandoned the bathing suit act, luckily for him as he crashed at one point. A hell of a brave man!
Then we have this totally weird Ben Biker act, which took place in Germany, and very likely nazi Germany by the look of the photograph (the nazis loved allusions to the Roman Empire) and the probable date of the BMW machines used. From this pictire I cannot quite figure out how he actually made the thing work. Where are the controls in terms of acceleration and braking? Maybe it was just a stunt for the picture.
How to carry a passenger comfortably on a bike has always presented a major challenge. Here is an original solution that has the added advantage of allowing the lady passenger to prepare a little liquid refreshment for herself and the rider whilst having her face (or other parts of her body) caressed by her gentleman friend. She would also be free to reciprocate; that is once she had finished dealing with the liquid refreshments. One expects that the rider avoids taking too many turns while in action in this manner.
I would not recommend trying this technique, any more than the other two, in the presence of members of the police force.