David Bowie and Mick Jagger's friendship was once, apparently, a friends-with-benefits situation. In his new biography of the Rolling Stones front man, "Mick," author Christopher Andersen describes how Bowie and Jagger coupled during their 1970s heyday.

"Where Jagger was still coy about his own sexual preferences, Bowie made no effort to conceal the fact that both he and his wife were bisexual and often shared partners," Andersen writes in an excerpt of the book published by the New York Daily News. '"Mick looked at David and wondered if maybe this was the wave of the future,' said Leee Black Childers, former executive vice president of MainMan, the management firm that handled Bowie. 'Mick was very conscious of doing whatever it takes to stay hot; David was the hottest thing around at the time.'"

Angie Bowie, the "Ziggy Stardust" singer's first wife, recalled walking in on the two in bed.

"Angie went upstairs to her bedroom, slowly pushed the door open, and there they were: Mick Jagger and David Bowie, naked in bed together, sleeping," Andersen writes. "Both men woke up with a start. 'Oh, hello,' said Bowie, clearly taken by surprise. 'How are you?'"