Katy Perry Leaves Sweet Comment on Ex-Boyfriend John Mayer's Instagram for His Dad's 90th Birthday: Pic!

They may have broken up, but the two still care about each other -- and their families.

Katy Perry's still got love for her ex -- and his family!

The Witness singer left a comment on John Mayer's Instagram on Wednesday after The Search for Everything singer-songwriter shared a sweet snap of him and his dad in honor of his pop's 90th birthday.

"Happy 90th Birthday, Dad! Leave doting comments about my dad below," Mayer, 39, captioned the pic. "He’ll love scrolling through it. Also please stop this train. Thank you."

"Looking fantastic as ever!" Perry commented. "Happy birthday friend."

instagram.com/johnmayer

A happy 90 years, indeed!

Mayer, who openly spoke about his former flame's influence on his most recent work earlier this summer, shared what song about an ex makes him so sad, he can't play it live anymore.

Watch the video below to find out which one.