Which Celebrity Couple Got Cozy in Philly on the 4th of July?

Red, white and 'I Love You'?  This on-again-off-again couple hit the city of brotherly love to celebrity our nation's Independence Day.  And they look anything but independent.  Can you guess who they are?

It's Katy Perry and John Mayer.

Katy was in Philadelphia to spend time with John while he performed for thousands at the Welcome America celebration, and shared this intimate photo as she cozied up to her man.  And it's pretty clear despite their see-saw romance that there are still plenty of sparks between the two.  Don't they look adorbs in their matching stars and stripes ensembles?  Very festive.