I know this story has been searched for on the comm before, but I wasn't able to find it in the "retail" or "store owners" tag. I know there's a podfic of it.
Jensen owns a comic book store, and Aldis works for him. Two of his customers (I think they were the Ghostfacers actors) asked him to settle a Batman vs. Superman question (I'm sure it was Batman, not so sure about the Superman part), and after getting them to narrow down "which" Batman they meant, he answers "Deadpool." Apparently, Jensen always answers "Deadpool" to "vs" questions. Aldis tells the guys they aren't going to like the answer before Jensen gives it.
IIRC, Jared has been coming in once a month for a book for his niece, but he finally works up the nerve to talk to Jensen and his ice breaker is "Han shot first!" He may have been a teacher.
ETA: FOUND!!! by
kruel_angel in about 15 seconds!! It's
Dork Reign: A Tale of Geek Love by
saone77. And it wasn't Superman, it was Wolverine. Knew I was off on that. For anyone interested, here's a link to the
podfics by the wonderful
reena_jenkins