I think your best bet is to find out what he likes. Cars, tools, Star Wars, books, etc. If he likes it, it won't be girly. Maybe when you visit him, you can kind of check out his room. Is it full of Legos, dinosaurs, girly posters? Boys that age are strange. Some are still very little kidish and some are much more mature. Look around and listen. You'll find something that you can both love.