I did something like that once, although pretty casually. I didn't expect any specific reply because I didn't want the answer to be generated by my own expectations.

I began to walk towards a woman that was sitting down at a two-chair table by herself. She had dirty-blonde hair down to her shoulders, and was wearing a light pink cashmere sweater, with sleeves that stopped at her arms. I leaned over, putting my elbows on the table, and held an imaginary microphone in my right hand, holding it out to her.

"You're not real," I said.
"I know." The DC shrugged it off.
"What's it like to be a dream character?"
"It feels real to me."
That's all that happened... This thread makes me want to do it again, though!