I have a friend from college who was overseas for the last few years. He has since come back home and seen me 10 or so times since I started transitioning. He continuously struggles with pronouns and frequently uses "girl" with me. At first I would gently correct him, then it progressed to a joking "I don't know who you're calling she because I have more facial hair than you", and now it's a much less patient correction.
He recently moved into my neighborhood and my roommate and I have been hanging out with him more. It doesn't seem to matter who is doing the correcting or what tone it's done in, nothing fazes this guy. It's literally in one ear and out the other. He always brushes it off with lines like "oh, you know what I mean" or "it's just a filler word/phrase, it doesn't mean anything".
He's been a good friend in the past. My roommate and I both agreed that he's slow on the uptake and may take longer to really "get it". My girlfriend thinks he's a jerk, and doesn't get any vibe of him being sorry for what he's doing, which I also agree with. Intention matters a lot more to me than the misgendering. I can deal with it as long as he understands that he's wrong and feels bad about it, but I truly don't think he does despite knowing how much it bothers me.
I am getting to the point where I want to cut him off, but I don't want to do that until I've exhausted all of my options. If you've had friends/family/acquaintances that were apathetic about using the right terms with/for you, how did you address it to make it finally sink in for them?