Time For a Costume Change

Billy's suit is destroyed by the acidic lawn sprinklers so he's forced to forge ahead unprotected. I didn't want Billy to have to spend the whole story in a cumbersome suit, and I like that it maybe wasn't necessary in the first place. Was Billy just wearing a play costume that gets wet with water from the sprinkler so he ditches it? Or was he completely imagining the suit? Or did his adventure start out more sci-fi, but he's not constrained by genre? Either way, he's free to play as he see's fit and the melting suit gives a sense of peril to his journey.