There is a liminal space created between the powerful person and the person who is the target of unwanted attention, a liminal space between outright yes and outright no -- not a maybe-yes or maybe-no -- but more of a hovering, a being caught and not knowing where else to go or how to move without making things much worse. So you stay put. You hold the person off as best you can without causing them to retaliate too terribly, and because you know they can retaliate if they want to, that they have the power to do this, that they could decide to ruin you for displeasing them or rejecting them too forcefully.