Cisco was thrilled to have Caitlin back and he ws looking forward to talking with her. If didn't matter that she didn't remember being here before, he could fill her in on what had happened which actually hadn't been that much since her stay had been short. He knew she'd have a lot of questions for him since he had been at home with her yet he was also here. It was a lot to process but after all they'd learned about time travel and alternate versions of Earth, not to mention that Caitlin was a genius, he knew that part of the explanation would be the easiest.
He knew that Nora had spoken to her and had told her that Cisco was her father so that would take come explaining. Had Cailtin met Lustre when she was here before? Cisco couldn't remember. It was hard to keep up with time here (which was the whole point of the project they were working on) so he had no idea exactly how long Cailtin had been gone.
When he saw her sitting on the beach, he couldn't help but smile. It was good to see her again, he'd missed her a lot more than he'd realized. "Hey," he said as he plopped down next to her. "it's good to see you."