Katy Perry and John Mayer break up again

Katy Perry and John Mayer have been up and down (or "hot and cold," if you will) for years now, and E! News has exclusively learned from a source close to the couple that they've called it quits again.
According to E! News:

The insider didn't offer any specifics as to the reasoning behind the two celebs' decision to break up, but notes that they're known to make-up time and time again (we know), so it's very possible these two will reunite in the near future.