What a cute threesome!

Katy Perry struck a patriotic pose alongside her grandma and President Obama.

The 28-year-old songstress Tweeted the above photo and the following,“May I exclusively present what might be the cutest photo ever taken: Me, Gma & POTUS!”

The "Firework" singer recently performed at two of President Obama's rallies ... one in Vegas and the other in Milwaukee. Guess we know which side she's on!

We must admit, Katy's 91-year-old grandma is adorbs!