Katy Perry And John Mayer Coordinate Their Outfits For The Fourth

Katy Perry and John Mayer are definitely back on, and the two celebrated the 4th of July together ... in matching outfits! Katy posted the photo of the two above and wrote, "Whose broad stripes and bright stars?!" Cute!

Katy was with John in Pennsylvania yesterday to watch him perform at the Philly 4th of July Jam at Benjamin Franklin Parkway in Philadelphia, and a source tells Us Weekly that she "watched every second of his performance, singing along to every song and dancing. She was so into his performance and gave him a big hug and kiss when he finished afterwards. She seemed all about him."

Think their romance will stick this time around?