No, what you feel is the cup pulling on your lips, feeding spatial information to your brain then to your arm. The cup is NEVER under the control of your head, only ever the hand. Your hand pushes the cup against your lips, your lips push back to keep it from hitting your teeth. The cup is never truly stationary against your lips, it is always moving a little, and this feeds back positional corrections to your arm and hand to keep it in position. If it was truly the way you describe, there would never be a reason to dribble while you drink when tilting your head, and that is plainly not the case. People dribble. If you have 'unrealistic drift' that is because you haven't tweaked the frame well enough.