look your young and it makes sense you wouldnt understand how things like this work. but if you looked at it from an intellectual standpoint you'd see that its in his right to get this guy to buy him stuff, and since the guy is a grown man, i think hes smart enough to make his own decisions and do what makes him happy ;)
Taking advantage of somebody to get them to buy you something is scum-baggy and immoral. You are a prick.
I don't understand why Stocking thinks that her opinion is valid, since I doubt anybody in real life would actually want to partake in a relationship with her.
You need to clearly establish your relationship with this guy, and let him know that it's not going to go any further. The best thing to do is be vocal. Sure, it may make him upset for the time being, but in the end it works out much better than him being led on, and then being disappointed.