A source tells E! News exclusively that this may not be a permanent split, and that once things calm down with their schedules, they could get back together.
"They both really love each other," our insider says. "They've always been hot and cold and on and off."
The source informed E! News on Wednesday that Perry's upcoming world tour was a big issue for her and Mayer, saying the "Dark Horse" singer was definitely putting her work first, but adding that it's unclear whether or not her tour was the actual final straw.
Perry is booked solid from May until November after recently adding another leg of her tour. She announced on Twitter yesterday that she will be spending November in Australia and New Zealand.
Mayer is also scheduled for a worldwide tour from April to June.
The two first went public with their off-and-on romance in summer 2012. They split briefly, reconciled, called things off again last March, but then seemed to be going strong once again.
Meanwhile, after news of the split broke, Mayer was snapped stepping out solo as he exited his hotel in New York City on Tuesday.