Katy Perry & John Mayer: Love Gone Wrong

03/23/2013 at 10:15 AM EDT

Katy Perry isn't one to miss catching up with girlfriends. So on March 17 the pop star spent the morning hiking in Los Angeles with her pal Selena Gomez, then showed her support for the actress by checking out Gomez's latest flick, Spring Breakers, at a movie theater. That same weekend John Mayer set up his own ideal night in Hollywood. The rocker was spotted at the Upright Citizens Brigade Theatre on March 16, hanging with close friends, including Saturday Night Live cast member Nasim Pedrad and comedian B.J. Novak, who performed that evening. "He was definitely low-key but looked like his usual self," says an onlooker. "He was in a good mood and hung out in the lobby afterward talking to his friends."

But one VIP (Very Important Perry) was missing from Mayer's group and has been notably absent from his side for almost two weeks. Following seven months jam-packed with relationship milestones meeting the parents! house-hunting! a ring! (see right) the once-inseparable couple have been spending time apart in L.A., showing signs that their romantic fireworks have flamed out. While reps for both Mayer, 35, and Perry, 28, had no comment when asked about the pair's split, Perry may have said enough on Twitter. After gushing on March 2 during a getaway to Montana that "my boyfriend is taking me to a kitten shelter in his truck. I can't think of a more perfect Saturday," she was singing a very different tune on March 15. "Perfectly put, by Daughter," Perry tweeted with a link to the indie-rock group's single "Landfi! ll," which includes the lyrics, "Throw me in a landfill/ Don't think about the consequences . . . I want you so much, But I hate your guts I hate you."

Of course, Mayer has earned a reputation as Hollywood's most outspoken heartbreaker, with a string of on-again, off-again romances with A-list women and a history of comparing his ex Jessica Simpson to "sexual napalm" and unwisely addressing his relationship with Jennifer Aniston in an impromptu press conference outside his Manhattan apartment. So when friends found out last summer that Perry had set her sights on him, worry set in. "It's like wanting to find a solid guy and going to a meat-market bar to find him," says the Perry pal.

And Perry had found herself in love with another Mr. Wrong before. As her 14-month marriage to actor Russell Brand, 37, unraveled in 2011, "I started to realize . . . that fairy tale that I had is not true for me right now," Perry confessed through tears in her concert movie Katy Perry: Part of Me. Telling fans in the film that her perfect partner is someone who "won't be threatened or have weird motives," Perry hinted that her soaring success (she is one of the top 5 highest-paid female musicians of 2012, according to Forbes) was a cause of friction with Brand.

Some say the same tensions rose between Perry and Mayer. "He's very defensive and comes across as extremely jealous of her career," says one Perry insider. "He's basically using Katy, who fits into his plan to stay in the spotlight right now," a source adds of Mayer, who has been recovering from vocal granuloma surgeries and retreating to Montana while on vocal rest for the past year.