You had managed to convince the widely known "lunatic magician" to sit down for a meal with some... coercion. That coercion being defeating him and tying him up. When he calmed down, and you undid his bindings, he was willing to listen. So, you told him everything that his people had told him. They weren't happy, in fact, their immortality served more as a curse than anything. They couldn't even eat anymore.

"I see..." He ponders for a minute, before taking out his spell book. Before you can react, he puts a hand up. "Don't worry. I'm not going to harm you. Thank you for your input. Eating, yes?"

Vines start to curl up around your feet and hands, restricting you from moving. "I have just the solution. It's quite simple, really. You won't have to worry about food, for the rest of eternity." ...Did he think force feeding was a solution?!