The following is purely my opinion based on my own life experiences.

A quick side hug for brothers and sisters, so nobody's business is rubbing all over my business. My kids get hugs unreservedly because I gave birth to them and don't consider hugging them to be a violation. A hug between lovers is certainly different than a hug between client and T, but if the front of my body is mashed up against the front of someone else's body, and their arms are making a cage around me, that is SO not going to happen.

Hugs will be reserved for family and extremely close friends.