Middle Son has never liked having his fingernails clipped. As he has gotten bigger and stronger (he's now 5'8", 175 lbs, and very strong) its gotten harder and harder. About a year ago, I gave up on using a nail clipper on his thumbs and pointer fingers. He struggled to much. I was worried that I would end up getting a finger broken. I switched to using file. I continued to use clippers on the other fingers. For some reason Middle doesn't object as strongly to that.
Also about a year ago, we started doing ABA therapy again with him. Unlike virtually every other employer, Microsoft's benefits package includes specific coverage for ABA. On of the things that I told them I wanted to work on was using fingernail clippers.
Wednesday night, Middle allowed me to use the clippers on his thumbnails and one pointer finger. I was very excited to see the progress.