This is a journalistic nightmare concerning Mr Bowie's bisexuality.
Angie Barnet (his first wife) was openly bi. It has been evidenced that she had other men with Davids consent. At the time (1970-2) he denied being anything BUT straight. In 1972, at the height of Ziggy mania, NME run the headline "I'm Gay" following an interview with him. This in turn instantly made him a gay icon and with 10 percent of the population estimated to be gay, made him a global superstar literally over night.
With in a few months he refuted this, but the press was not interested. And he couldn't have cared less. During this period, he had near enough broken up with Angie and was dating Ava Cherry.
There has never been a man come forward saying he has slept with Bowie or any evidence whatsoever. Assuming the man is worth half a billion, I am sure there would be a few stories.
However, come 1991 when he was firmly engaged to Iman, he publically said at the Freddie Mercury Tribute gig "We slept with a lot of the same people". If you watch this there is a cheeky glint in his eye and given the fact Freddie was a proper gaylord, and the whole aura of the occassion, journalists did not really pick up on this.
So to answer your question, Mr Bowie, to the best of my knowledge and belief, has never had bum fun.
Evidence of a weird sexual nature has only come from two sources.
1) 1987, a report from some Dallas bird that he raped her after a a night out. It now appears she is a crack wh0re desperate for attention
2) 1974 (he most coked out phase) a report from a Philladelphia woman that he made her take a 10 minute cold shower and act dead so he could act of a fantasy of necrophilia. Who knows?? Drugs screw your mind up.