Headcanon that when someone gets injured during a fight, (the clearly underaged) Robin at the time sometimes run into the nearest convenience store and buys vodka to clean the wound~
Imagine.......When Dick is Robin, he gets into a fight with a group of gangsters, and a civilian gets injured. Panicking, Dick runs into the nearest convenience store, looking for something to clean the wound with. Naturally, the workers are very confused as to why a little boy in a brightly coloured costume is attempting to buy a bottle of vodka. They eventually sell it to him on the grounds of "Batman would probably beat us into a pulp if we said no."
Over the years, this happens several more times, even continuing whenever there's a new Robin. Convenience store workers in Gotham have gotten so used to brightly coloured children coming in and purchasing alcohol that when a new person starts working at one of the stores, no one even thinks to explain what the hell is going on.
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Store Manager: —and last but not least, remember to ask for an ID before selling alcohol to anyone who might be underage.
New Employee: understood.
Robin: *enters, in full costume and covered in blood. walks to the back on the store, before returning and placing a bottle of vodka on the counter with a thud*
Store Manager: *immediately begins ringing him up*
Store Manager, smiling: that'll be $20.
Robin: *hands over the money and leaves with his bottle of vodka*
New Employee: ...
New Employee: ......
New Employee: ........that was a child. That was a child in a Halloween costume. You just sold alcohol to a child in a Halloween costume.
Store Manager: oh yeah, that's Robin. We don't actually know how old he is.