The group was ushered into the far back corner of the tented patio and took their place at a cluster of tables, with servers and security keeping an eye on them, reported People magazine.
Mayer, 35, wearing a dark shirt under a grey fitted blazer, shook hands with everyone, while Perry, 28, looked stunning in a short-sleeved white 50's style cashmere sweater and a fitted metallic patterned shirt as she chatted with their friends.
Perry and Mayer called it quits after a second time.