What do I do with the signed birthday card?

Although he goes out of his way to celebrate other people, a few weeks ago, I found out the hard way a beloved coworker hates celebrating his own birthday. (We wanted to surprise him with brunch at a restaurant and he refused to go, having a mini tantrum). Instead a couple of managers suggested doing something like a holiday / end of year or one party celebrating all of our birthdays' that way, he's included. I'm feeling a bit depleted with his response. What should I do with his signed card?