Most guys, nerdy or not, consider their friends to be an extension of themselves.
In their passion for fact and truth, nerds can run right over other people's emotions.
Annoyingly, you can't treat their own feelings the same way.
Use these comments as a place to start but, as always, you'll need to work it out for yourself.
Make an effort to really know the person rather than the label. they are masters in their field, and are deservedly self-confident.
Try also to keep up with the latest news of his favorite books, movies or games.
Wouldn't you rather he discussed it first with you, rather than his on-line community?
As his partner, your job is to be his number one cheerleader.
Heavy-handed teasing will drive him back into his shell. There's nothing nerds enjoy more than a reasoned discussion.
Understand and accept their unique tastes, take some interest in what they love doing and genuinely share in their passions and concerns.