When I do dream about diapers, it's usually either a dream about trying to secretly indulge in my diaper fetish in a semi private setting, or a dream about playing a videogame about a diapered character. If I have a dream about using a diaper, it's usually a wet dream, unless I'm woken up from it fast enough.
Once I had a dream that I was playing a 3D platformer/3rd-person shooter that played like Ratchet & Clank, but you played as a loli supervillain, swapping control between herself and her henchmen, spread out across a large map, trying to pull off complex schemes and heists within a time limit. The game has a few parallels to the Misadventures of Tron Bonne, but the main character designs were very obviously inspired by Pinki and the Pinki Gang from Super Magnetic Neo, so you're playing as an evil tot mastermind, with an assortment of competent masked henchmen, robots, and super strength mutants. After a successful mission, you get to perform tasks to improve her temperament, including an unlockable option to play a POV diaper changing minigame as one of her henchmen. The diaper has physics, so you could get a sense of how heavy and squishy it got, both in the minigame and during normal gameplay if you pay close enough attention.