What do you do when someone commissions you and either during the commission process or after it's complete, they assume that you are now friends? I have had several commissioners turn into friends, but in all of these situations this happened naturally. I'm talking about the people who try to force friendship on you either in the form of constantly writing you emails, attempting to IM you despite you specifically saying you don't chat, or contacting your other friends/significant other completely out of the blue for no other reason you can think of other than they want to try to get closer to you. They might even mention later that they commission artists "to make friends", and you are caught off guard and may not feel the same.
I know several artists have had this happen to them as well, which is why I'm asking what you would do in this situation? It's not threatening, you are just not interested. Just because money changed hands does not mean a friendship has occurred. How do you go about letting this person know that this is not the case. Do you even bother? Do you put something in your TOS expressing this? Do you ignore them completely? Any advice is appreciated.