>>6043423Water would flow out due to surface tension and crawl along the outside of the bag until it froze.
You wouldn't lose much water that way, but over time you'd have quite a few holes in the bag, which would create places where it could rip if it's dragged along it's orbit.
Two objects that are in even the slightest different orbits will drift apart over time. Normally this doesn't matter much, but the mass of water would be enormous and the bag would be very weak.
This could be dealt with using a carbon fiber net, staked into the surface of the asteroid to help keep it in place.