David Bowie, the visionary rock god, turned down collaborating with Coldplay, that band your douchiest boyfriend liked, because he thought that the song they had written for him wasn't very good. Of all the fantastic artistic choices Bowie made in his final years, or any years, this is among the best. Perhaps most amazingly, this anecdote comes directly from the horse's mouth, or at least the horse's drummer. As Coldplay drummer Will Champion told the music journal NME:

The Coldplay lads once tried contacting Bowie to see if he would consider collaborating with them on one of their songs in which they had a "David Bowie-type character". 

Singer Chris Martin sent him a letter asking him to be involved and, according to a smiling Will Champion, Bowie replied, "It's not a very good song, is it?" Coldplay's reaction was to not be overly phased – Champion notes, "He was very discerning – he wouldn't just put his name to anything. I'll give him credit for that!"

Sources: NME