What should I put on my wedding program? Very specific question!?

My step-dad is going to be a groomsman in my wedding. He is very close to me and my fianc�, and he is my fianc�'s boss. I'm wondering what other people think is appropriate...Next to his name on the program, should I put "step-dad of the bride"?? Or put "friend of the groom"?? Neither seem appropriate, so I'm wondering what other people think!