Buddhism helps us to overcome our endless ego grasping mind to open up to something so much more spacious and genuinely meaningful.
When one has a decisive realization of the inherent nature of the mind, which has no ego, it has no sense of duality between oneself and the cup, and a deep sense of interpenetration of the whole dharma. Then whatever we do is spontaneously perfect Buddha activity. And anybody who is even slightly tuned in will get a very deep experience of that.
A realized being would not be making any fresh karma because karma is very much connected to the ego but would still be receiving the results of past karma.
