I plunked my teabag into the cup and filled it with hot water. On the way back to my desk, I noticed that my finger was really hot. And wet. Seems my cup had sprung a leak. So I grabbed another to put outside it and contain the leak and wandered back. After a few minutes, I figured if the leak were sizeable at all, it would fill the outer cup and make a mess. So I picked up the inner cup and let the leak go. It was pretty fast, but I got tired of holding the cup so I poured the water into the second cup.
Then I looked at the first cup. The styrofoam had been eaten away by the tea. There were scary chunks missing. I presume this is why my cup sprang a leak in the first place. I dumped the tea, not wanting to actually drink melted styrofoam. Today I have a steel mug and killer tea.