Talking about BDSM with my therapist?

I really wish I could talk about my BDSM relationship with my therapist. It's really hard to explain my D/s dynamic with out it sounding abusive so I end up not talking about my relationship at all. How do you explain to a therapist your relationship? It's such a big part of my life, we are 24/7 so I'm basically lying about part of my life in my therapy.

Edit: I don't go to therapy FOR my relationship, I just think its such a huge part of my life, I want to be able to talk about it.