Secretly when the one who is holding you captive is distracted.
Faking displeasure? Oh, that is a toughy. I've consulted with my friend Blanche on this one.
Blanche: Give him a disdainful look. Act bored, as if this isn't worth your time. The best way to keep from physically reacting is to learn how to school your face by watching yourself in the mirror. The body can be controlled as well by similar methods.