Firstly, PistolPete, apologies if I've singled you out, I'm trying to respond to this whole thread. I'm not 100% clear on how reply works.
Back to the topic at hand. I think it's awesome how open most of you seem to this particular reciprocal act, but it seems a misleading to say you always have to do whatever your partner does or you're a being a hypocrite. If you're a submissive, and your partner is a dom, neither of you would find the option of switching positions appealing. That doesn't necessarily require that you find what the other person is doing is repugnant, just that it's not for you.
I like my sexual partners to have boobs, and from what I can tell my girlfriend would prefer that I not have boobs. It seems to me that as long as you're able to communicate your affection for your partner in some way, you don't have to do it exactly the way that they do.