I never hugged with a therapist but, for me, I would not like it in any other way but a spontaneous act where it is clear that both parties would like and welcome it. For me, it is not something to discuss, ask for, or offer and I definitely would not want it on a schedule, like at the end of every session, for example. I also don't like when people ask for physical affection in a relationship/situation where it is not clear and obviously desired by both, it feels forced for me otherwise and loses the appeal. So, for me, a hug is a form of affection and not a treatment (like a massage) or a social convention (like a handshake) and I would only like it spontaneously.