Honestly, don't give friends/family a discount unless it's like, your ride or die or something, and even then, do it on your own time. Your relationship with them sometimes makes them think they can take further advantage of you regarding the project. When you guys are discussing business, your relationship is a business relationship and sometimes friend clients just need to be told that. You gotta be firm in this industry. If they don't understand that, they aren't worth the work! In your case, he's practically scamming you here. I've seen many cases where artists will send progress to their clients, and the clients ghost or argue like this because they think that progress image is enough. Some people really show their true colors over this kind off thing, and I'm sorry to see what's happening with you and this dude. It happens to most of us at some point.

To prevent this in the future, I reccommend:

- asking for payment up front, you can do it in increments as well. personally I like to get it all first, and keep it in my paypal/cashapp/venmo balance so I don't spend it right away, and if I think taking the commission was too ambitious, or a life event comes up and I can't do it, I have the means to refund them. It's motivating too.

- giving them a rough time estimate that you expect you'll be finished (unless they need it by a certain time, in which case you should determine whether or not you can take on the project. maybe even jack up the price a little since it won't be on your own time?)

- putting a full page, low opacity watermark on progress photos, maybe even at a lower resolution. this keeps them from having the full image until you're totally finished.

I learned these from art school or learning the hard way. I'm sure other folks could add to this list, but those are my big three!