I had my first child when I was in my 20's, and he is now in his 20's.  Although I do like young men, I will never meet nor have sex with a man who is closer in age to my son than to me.  This is not a reflection on you but rather a personal preference and a comfort level that is not up for negotiation.  I would never be expected to have a sexual attraction to a contemporary of my son's during his infancy or childhood so please do not expect me to have one simply because that contemporary is now in his adulthood.  I am still old enough to be your mother!!  My comfort level is + or - 10 years of my own age.