I'm playing a Firbolg character. The Firbolg's racial Firbolg Magic trait (VGtM, p. 107) allows them to cast disguise self once per short rest. As part of the character's backstory I want someone to be able to see through his racial ability to disguise himself, and instead be able to see his normal form so that rumours start spreading about this creature that's new to town.
I haven't been able to find any item that can make this possible, I'm new to the game so there's no surprises there. So before I scrap the idea and just go with "he ran out of time on the spell" or using dispel magic.
Is there a magic item, spell, etc., that can make it so that you can see through (specifically what's underneath) a disguise self spell?