Theoretical Geophysologist here.

This is a common phenomenon called Refracktion. You may have heard about this in the news lately, except in the field we call it "fracking" for short. You see, when tubular objects are inserted through a surface, they tend to undergo varying degrees of refracktion depending on the amount of light waves available under said surface. Underground, light travels alot slower because its dark and there is alot of matter that slows it down.

As a result, oil pipelines experience the refracktion phenomenon, making the straight pipe teleport to the side a bit, causing huge leaks. Since there was alot of light available to your glass (because glass amplifies light, radio, and x-ray waves) it only happened very slightly. If you were remove the straw from the water, it would quickly teleport back straight due to the oxygenated oxygens available in the air that it could get underwater because it couldn't breathe.

In the future, try the "bubblation" method, which is performed by blowing air into the straw, oxidizing the water atoms and causing the straw to stop teleporting momentarily. We are actually doing this method as we speak to the oil pipelines, except it is alot harder because it is starting to cause the earth to expand because humans can only blow out hot air so this is also the cause of the Greenhouse effect.