Maybe I'm too laid back to be worthy enough to exist, but.....whoever buys the 'sketch' may have some modifications. Even if the artist isn't going to allow such, still. Things can change and have a completely different *feel* each time they're redone. And even if it doesn't, meh. If this had happened to me, I'd tell them it's fine, but just warn me next time, and we can do a trade where we're each other's practice for a pose we want sell off....make it a thing even. Yet tell them to warn people if they do it with anyone else before hand because it is something that people may get their panties in a twist about. I don't think it's really severe enough to post a beware, but again, I'm a loaf.