In my trolling for blog topics, @atlloki asked me "As a switch could you/would you sub in front of or to someone you've topped?"
My short answer is that I don't switch with individuals: Whether I top or bottom, I generally fall into a role with that man. When I submit, I tend to stay in that role with him, or at least want to. When I top, I enjoy that experience and fear that if I try subbing to him, I won't want to return to topping him.
It's more than fear, it's also a comfort level. Defined roles mean knowing where you stand with someone and knowing what's expected of you. Call me conservative, but predictability, while it might not be sexy, is certainly comfortable.
Other considerations that may affect switching with and around others - ongoing relationship like I have with my partner, negotiations about what will be going on (I have experience the type of scenes I dish out as a top, but I don't enjoy them myself). My husband and I don't have a power exchange relationship at all. We made a conscious decision to remain complete equals. As such, my machismo gets in the way when I bottom when he's around but not directly involved. I obsess about what he's thinking of the things I enjoy doing with others, worried that he'd get jealous of what someone else is doing with me, (or more likely that he'd be jealous that it's not being done to him).
The answer to the question really depends on the men in question. I'm just an emotionally delicate man, I guess.