Be honest and that shows you care. Men often deny early balding and by the time to stop denying it, the are past the point when they might have prevented or reversed it with medications. This goes to extremes and the denial can occur over a generation to the point where men can’t even see what happened to them such as those with the awful comb-overs whose wives and family never say a word. I know your question is really about early balding, but by being open and frank, you can show how much you really care and take a load off of his back.