cup sealed in water

 I decided to take a bath. I emptied out my cup and put it back in really fast. I entered the bath soon after and I guess I didn't give the cup a chance to seal or open up all the way. I got out of the tub maybe an hour later and noticed my cup leaking when I dried myself off. I checked it and it was full of water and "other stuff". It probably sealed while I was in the water.

 So yeah my advice to you all is to make sure it's open and sealed properly if you empty your cup before swimming or taking a bath.