The böglyft was pioneered by two guys in Sweden and has since become a world-famous activity.
When performing a classical böglyft, the lifter supports the flyer's torso with one (preferably right) arm while his other arm supports the flyer's (left) leg and also maintains a firm grip of the flyer's penis. An erection is preferred, be it a jokeboner or the real deal.
Style points are awarded if the flyer's underwear is down by his ankles.
A photograph of the original böglyft can be found here (warning: penis clearly visible):