My forty two year old son has disassociated himself from his close relatives and does not want to get married. I wonder if he is gay

 

Not everybody wants to get married. Not everybody who is single and older is gay.  Instead of wondering about who he sleeps with, you should worry about why he is distancing himself from his family. There are several reasons why people disassociate with their families.  If you really care for him, find out why by asking him in person and listening to his answer. Show him you are a good father by being there for him no matter what.  Good luck!