Answer:
In a galaxy, the expansion of the universe actually does not have any effect, because the force of gravity is enough to kinda keep the celestial bodies in their orbits.
Now, the expansion can be seen between galaxies (according to the Hubble's law, the far away is the galaxy, the faster it seems to move away), so the forces between stars actually will not really change, and the forces that the stars are experiencing by bodies in other galaxies are almost depreciable, so nothing will happen.
