Attraction is different from transference. If you want to jump in the sack with your new T right off the bat, that's most likely just plain ol' chemistry. And there is really nothing therapeutically damaging about thinking your T is hot and letting those thoughts run through your head; it's fun! It becomes a more delicate situation when you start wanting to act on those feelings, or when exercising those feelings becomes the primary motivation for therapy, or you're suffering real pain from unrequited desires and/or love. Then, it needs to be aired out and examined for what it can teach you, and to put those feelings in perspective and keep them from dominating your emotional life.

As nicoleflynn said, it really is just...feelings. And learning to know and deal with them is part of why we're in therapy to begin with.