It sounds like this is about him too. He wants to see you. He misses you and wants to wrap his arms around you in a warm brotherly hug

Do you think you could wear something light weight but long sleeved and be a little warm, just for the visit?
Or, could you tell him ahead of time that he will see the cuts?
(I don't know, just thinking out loud, but possibly subconsciously you wouldn't mind if he sees, as they represent your deep pain )

So, he's coming to see you. Will you make a cake? Bake cookies? Some other kind of snack to munch on while you chat? Will you have music playing in the background?
It sounds as if you feel this is a kind of invasion. Making plans for the visit, like snacks, coffee, tea, soda, etc can help you feel in control.