Getting taken advantage of

Recently, I offered to deprime and clean a considerable amount of 9mm Luger brass for a person.
I did it out of charity for this person, and if they decided to repay me somehow, fine. All the better for me. If not, then I wouldn't have complained. This person is very mercenary and doesn't understand charity very well, if at all. They asked if I wanted anything for doing the work. I said that if they saw fit to compensate me with some of the brass, then fine. I would have kept some of it. If not, well then at least I did a good deed. At one point I was even going to reload some of this brass into rounds for this person. I offered a fair price for my labor as long as the person bought their own supplies such as powder, slugs, and primers.

Alas, tonight while settling a food bill, this person decides to use a buy one get one free coupon for his share. He doesn't share in the bill and expects me to bear the brunt of both the bill and the tip. I was quite upset and was vocal about it. I tend to be generous with my friends and acquaintances as I was taught by my parents. I expect others that I associate with to be the same way, otherwise, they are not welcome in my circle of friends. I've ended friendships over this before.

This just pissed me off and I hate being taken advantage of. I learned a lesson about this person, and will be on my guard in the future.