What if I have been giving him stuff but haven't been getting anything in return?

This could be happening for a few reasons. Is he tight on money? Is he saving up for something? Maybe he just hasn't thought that you might like something back? It's funny how often people don't realize what you feel should be obvious. The best thing to do in any situation like this where you don't understand something is to just ask. Communication is so important for any good relationship to work. Don't accuse, just ask, "I've been getting you presents, but you haven't given me anything. I'm not mad, but what's up with that?" After all, no one would really know the answer to that in the end but him. And telling him how you feel will help him better understand you. It also helps to not hang expectations on your gifts, otherwise they're conditional obligations and not gifts.