John Mayer JMayerMKelly120907_01_X17.jpg Say what you will about John Mayer, but he's most definitely a man who's willing to accept responsibility for his decisions!

Page Six reports that, just before the news of Johnnifer's romance broke, Mayer gave his ex Minka Kelly a warning call. According to one of Minka's pals, John expressed sincere contrition for his actions, telling the actress "Sorry, but I'm really in love."

Of course, earlier in their relationship, Kelly's pal swears Mayer was singing a different tune. "[D]uring his relationship with [Minka]," Page Six's source says, "John mentioned 'I don't really get this Jennifer Aniston thing.'"

Guess he came around to the idea later!