First of all, Are you doing it in an environ with no gravity already effecting it? No.
Second, did you calculate the formula positioning them at the same distance? No
third, you neglect the sun's effect on tides.
fourth, is the cup a sphere? no.
fifth, would the distance the water moves be measurable to the mere eye? Of course not. The tides move a few feet. Shrink it down to that size and provide the following criterion, and we're talking a few nanometers AT MOST.