<p>He might be afraid you guys are going to drift apart if you study abroad. If your relationship is serious and worthwhile, it won't be affected negatively just because you happened to study abroad. If your relationship was doomed from the start, it might not make it through this, and the sooner you find out the better.</p>
<p>Seriously, chances are the guy has some trust issues or he is just clingy. You shouldn't let him stop you from going abroad. This is probably the best thing that you could happen to your relationship.</p>