Can you be a bit more specific on your suspicions? For example, is this in “real life” or “Tumblr life”? How do you know he is shy? What is your friendship like right now?
Believe it or not, Mr. TRD is not a guy who ever picked up a girl in a bar. I never was comfortable being that guy. Even looking back as far a junior high, I was always “hooked up” by friends or I knew the girl liked me before I had the balls to make a move. I feared rejection back then, and it really followed me up until college.
Part of it is I see those guys who hit on girls everywhere I go and just look at them like they are total clowns. Like 99% of the time just make women uncomfortable; fuck that. I never want to be that guy – the “going out to get chicks guy”. Ugh. No way.
So, to answer your question – he may just be shy but if you broach the subject of relationships and he doesn’t take the bait, he may be not interested.