It's pretty clear he's referencing Meek, but just in case you don't believe us...
Ch-ch-check out the shady moment and decide for yourself (below)!!!
[Image via JLN Photography/WENN.]
Along with Jon Bon Jovi, Earth, Wind & Fire, Stevie Wonder and Jennifer Hudson, Katy sang her heart out at the Nokia Theatre with hopes of re-electing the Democratic nominee.
She belted out one of her biggest hits, Firework (above) and then covered Al Green's Let's Stay Together to show the POTUS how it's done!