Weeks after splitting with Jennifer Aniston, John Mayer debuted a new tune, titled "Heartbreak Warfare," on his recent five-day cruise, Us Weekly reports in its latest issue, out today.

Before performing the song on March 28, he told the 3,000 fans aboard the Mayercraft Carrier 2, "It's miserable being around someone who's negative."

He then began singing the song, which includes such lyrics as: "If you want more love, why don't you say so?"

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It wasn't Mayer's only jaw-dropping moment: He also confessed to making out with celeb blogger Perez Hilton, who has bashed Aniston numerous times on his website. (Us Weekly reported on the same-sex smooch last year, but Mayer declined to comment at the time.)

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"F--k yeah, I made out with Perez," he told the crowd. "I just wanted to prove that I'm a sicker f--k than he is. I'll [have sex with him] until he runs away screaming just to prove a point."

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For more - including how Mayer found Aniston to be "obsessive-compulsive" about her looks and how she isn't "down at all" about their split - pick up the new issue of Us Weekly today!