With all the fake hair, contouring and Spanx hiding who we really are we tend to forget that men are sometimes hiding that receding hairline and trying to hold on tight to what little he has left. In Arab countries men try to hide this when wearing their ghutra and egal. Yes ladies, you may see a nice line of hair showing from underneath the cap but don't be fooled underneath it may lie a shiny chrome dome!
Ask him to come out in casual clothing, does he still wear a cap? If it doesn't bother you then you have nothing to worry about but if you think he has a nice head of hair be honest and ask if it is real or a mirage. The first male I met in Kuwait had what I thought was a nice head of hair, nope casual clothing day came and voilà there was a shiny landing pad staring back at me.
A friend of mine sent me a photo of him in the hospital with blood everywhere, I thought he had an accident but it was after his hair replacement treatment where they take individual strands of hair and transplant them onto his head, ouch!