To just expand on my grossed out but I'll get over it comment:

As a switch I've developed a mantra for myself that I should demand nothing of a sub that I myself wouldn't be willing to do if the situation was reversed. "Demand nothing more of others than you are willing to demand of yourself." I admit, I like a girl to swallow for me. This seems a more or less comparable opposite, and if the situation arose she would deserve the same standard that I'd asked to be applied to her.