I wouldnt say he sounds unethical at all. Not much info but from what youve written he could just be trying to reach out to you (i.e. show you that he can relate by sharing his youth with you). I don't believe in blank slate Ts. Hate that while concept. My T too shares some things about his personal life when he thinks I could benefit from it. From his personal life I not much about his life/kids and nothing about his clients. So no I don't think he is crossing any boundaries but only you can tell. If you don't like his sharing tell him so.
Honesty in therapy is vital. So I would encourage you to be open about your feelings too and not use Sam instead.