Minka Kelly and John Mayer is the latest celeb couple to bite the dust. "John initiated the split," a source tells Us Weekly. "He just wasn't ready to commit to Minka or to anyone."

And John's not afraid to let his bachelorhood go to waste! He's been seen partying with other girls in New York over the past month while Minka was in Los Angeles. "She was disappointed to say the least," an insider says. "She was really happy but wanted a full commitment." But that just wasn't in the cards for perennial playboy John: "From his perspective, he is single and has been seen out with her," a source says. "Nobody ever said he was planning a wedding with anyone." Ouch!