pros: they already have erotic books and normal movies, stocking porn movies wouldn't be that different other than medium.
cons: idk something about child safety, and you'd have to make sure people couldn't access the porn videos actually at the library unless you were gonna go full hog and set up masturbation booths or some shit.
idk, i'm leaning on the pro side bc i can't think of a non-puritanical reason to allow erotic literature but NOT video porn.
make a porn library next door. Don't make those nice librarians have to handle those post session materials.
This would be the best compromise. Plus a separate building with ID required before entry would ensure that kids can't get in.
Also, you sploshed on your rental and didn't clean it off? Sorry bub, you're gonna need to pay for a replacement before we let you check out anything else. We wouldn't want our porn librarians getting sick.