Imagine Jaime in the Batcave, working on a case with Batman, coming across the costume.
"Oh hey, a Robin costume!" *Tries it on for shits and giggles* "That's weird, it fits perfectly. Now I think about it, who was it made for? It doesn't look like..." *taking it off, notices nametag 'Jaime'* "Ummmmm." *Batman walks in*