I think we all started out riding, either recently or years ago, and would have liked someone to provide a little guidance. Give the guy a chance and ride your road bike with him... without being an a$$ about it.

Can't you show a little respect to a newbie and help him discover his current fitness level? Plan a ride that has a decent climb so that you can test his abilities. Maybe he will realize he needs to be in better shape when riding with you.