When: October 2010

In late 2010, prior to her 45 minute "marriage", Kim Kardashian was seen hitting the town in NYC with none other than John Mayer. Between the two of them, this pair of serial daters have been linked to half of Hollywood. Nothing of note seemed to materialize as far as a relationship goes, but they were spotted spending a fair amount of time together that fall. The curvy reality vixen was quoted as saying that Mayer's a "really cool guy". 

Smash Probability: A sex tape wasn't released and he never appeared on her E! series, so who knows?