Flight Instructor reported a ground conflict with an aircraft that over flew them while in position on the runway.

Narrative

I was conducting a training flight with a private pilot who has not flown in X years. Towards the end of our flight we were doing full stop taxi backs at ZZZ on Runway XX. The student was a XX year old man with plenty of 'war stories' and whenever we would land he would give control of the plane to me and continue to talk and look around. The airport was empty with no one in the pattern but us. On our last lap we taxied to the hold short of Runway XX and had not heard any prior radio calls. But while I was PIC my student was not using a sterile cockpit like I had requested. Upon making a position call stating I would be taking off XX staying in pattern. I checked final and did not see any aircraft on final. As I was crossing the hold short line I still heard no calls. Once on the very end of the extended threshold Aircraft Y passed about 100 ft above me executing a go around. He made no calls that I could hear and I did not see him while checking final. My only conclusion is that maybe I missed a call due to my student talking constantly and he was coming straight in and was above my wing. Aircraft Y is a very fast plane. After he went around we taxied off the runway and waited for him to land before taking off and leaving the area to the north. Considerations I will take forward as pilot are definitely to better position a high wing aircraft on the hold short line to get more visibility of final and really reiterate how important a sterile cockpit is during critical phases of flight. The student took responsibility for the incident but even though he is a private pilot. I take responsibility as his instructor since he isn't current and is in the early stages of a flight review.