I think it's a guy thing when they are concerned with trying to be appropriate. Best bet is to ask your T.

I had a boss who would hug like that. He was trying to be supportive, but he was weirded out by the contact afforded by the hug. We actually talked about it once because a bunch of us were getting on his case about it...

I don't often get hugs from T's (or anyone other than family & close friends). The first time I ever got a hug from a T, I remember it being really awkward. She asked if I wanted one, and I said yes thinking it was just going to be a quick "fake hug" that most people do. It was after a rough session. I was all stiff and stand off-ish, but she hung on till I relaxed a bit. It was weird, but also really comforting. Kinda felt like she was trying to stick all the broken pieces back together for me.