So Gillian attended the CAA Upfronts after party. Do we know if David joined her? A former Californication star, Carla Gugino, took a photo with G.

No, I think she was on her own at this party.
Side-note : she also attended the CAA party after the Globes, so I assume it was some sort of commitment. David isn’t represented by this agency, so he didn’t have to go.