6. The hair on top of his head is thinning
“It’s somewhere that he can’t see, so maybe he hasn’t noticed.” Even if his hair is clearly starting to thin, it can be difficult to say anything. You could try bringing up the subject in a roundabout way—“Apparently you should change your parting now and again, or your hair will thin faster”—and this might encourage him to realize it himself. Alternatively, you could just decide that bald men can be very attractive.