"No reason not to try it--hey!" Are they playing swim tag now? They can do that. Finn pushes off the bottom for a little extra speed so he can catch up for a return poke, heading off at a right angle toward the deeper waters so he doesn't have to completely lose his momentum. Maybe he should dive under to hide better? Opening his eyes underwater stings a bit but, like with his back, it's nothing he can't handle.

...It also gives him a less distorted view of the rest of Poe's body, which is no bad thing.