A water balloon is read as playful mischief and feelings about to burst. Getting splashed can stand for a harmless shock that breaks the tension.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.