Is this why Katy and John split up?

Katy Perry and John Mayer reportedly split up because of her upcoming world tour.

According to Us Weekly, Perry and Mayer called it quits because of the strain of Perry’s Prismatic concerts, which are scheduled to kick off in Ireland in May before crossing three continents through the rest of 2014.

An insider revealed to the publication: "She’s stressed about the tour, they’ve been fighting. It is probably for the best, because she is going to be on tour for forever. Of course this happens all the time, I can’t keep track anymore. But for now they are done."

Perry and Mayer – who first went public with their romance in 2012, before briefly calling it quits last March – could still reunite again, a friend claims, saying: "Not sure how long it will last this time but yes, it is off for now."

However, a third source wasn’t too confident, adding: "They’ve had rough patches, but this may be for good."