Washington: John Mayer was reportedly not happy that his now former girlfriend, Katy Perry , was on friendly terms with her ex-husband, Russell Brand.
The wannabe lothario didn`t like the 28-year-old`s constant mentions of Brand, and it created a tension between them that threatened to boil over at any point.
A source revealed to Radar Online that Mayer and Perry together were like a volcano just about to go off.
The source said that their relationship was incredibly volatile, stemming from the jealousy which they both harboured deep inside, and Perry was unhappy that Mayer constantly flirted with other girls and played up his heartbreaker image, even when she was standing next to him.
"But, Katy gave it back. She knew that she could push John`s buttons by comparing his flaws to what she saw was great in Russell, which he hated!" the source added.