He had heard. Not from Debbie herself, but he remembered seeing it on Cat Grant's storyboard for the Planet's gossip column a little while back.

"Oh, well, I won't keep you too long then." Clark says, pausing briefly to adjust his glasses as they start sliding down his nose. "Just wanted to give you a call and let you know that I'm actually going to be out in your neck of the woods next week and see if you wanted to grab lunch or something. Catch up."