Corrected entry: Breathing the air from a glass with a pen is physically not possible that far under water. It is hard to breathe that way at 60cm bellow surface. Any lower and it becomes impossible - the fluid pressure on the lungs is just too high.
Corrected entry: When Cleveland hears splashing in the pool the first time, he opens the door and holds a flashlight in front to see. The shot is of the light out of the door, it is very obvious that it is raining, as it can be seen with the light. However, the next shot is of the outside and its obviously not raining. nor was it raining before any other shots.
Correction: It wasn't rain; it was the lawn sprinklers. Sprinklers go off and on.
Correction: It would indeed be possible to breathe from the glass as both the air in the glass and the "breather" are at the same pressure. This is what a SCUBA regulator does, it provides air at the pressure appropriate for the depth of water. The only time you could not breathe through a straw is if you are breathing air from above the water surface and your lungs are more than 6" deep.