This is one of those questions where I might not know my true answer unless I see (and feel) it. But my hypothetical answer is that I think seeing her sub to a woman, or both of us subbing together to that woman, might actually be a turn-ON. I think seeing her sub to a man might be tougher.

That said, I have seen pro dommes who switch in the past -- I love doing sessions where I'm dominant the first 15 minutes, and then she "rebels" and takes control. The fact that she's willing to switch, obviously means she's doing it with other clients as well. Don't ask, don't tell, maybe