What would you do?

Come on man you know what you have to do - leave the tractor there and keep doing the driveway ,heck another month and you'll need it there to mow the lawn , if he comes out and says anything tell him to STFU and go about your business as if he wasn't there . Only a real POS Goof would even consider punching an 88 year old so your not going to do that , it's for your wife and her mom so just keep doing the right thing and ignore him .