On Saturday night, the two were spotted enjoying the Bjork concert at the Hollywood Palladium together.
It's being reported that the two met up discreetly and left separately to avoid paparazzi flashes.
Now, our lovely KatyKat has once again been linked to John Mayer, so we're sure Katy's keeping her platonic relationship with Robberz as flirty-free as possible. But that doesn't mean we can't fantasize about what their babies might look like! Ha!
[Image via Cousart-Rayne/JFXImages/WENN.]