Taking Sparky’s shorts has turned everything upside down for Rat. Sparky is confused and angry. Rat is confused with himself.
Why would Rat do that? Why would he want a pair of his best friend’s shorts? Shorts that Sparky has worn while training?
It’s not entirely clear what is going on here. But what is clear, is that whatever relationship Rat and Sparky had before Rat took the shorts - can never be the same again.