Your girlfriend's breasts slowly get bigger and bigger right before your eyes. Her breasts bulge out the top, sides, and bottom of her bra. Then you hear the distinct sound of threads snapping as the center gore of her bra gives way to her swollen mammaries. She slides the straps off her shoulders and looks at you and asks, "Are you going to join me or not?"
Again, my fantasy, no where near realistic as bras are built to hold in heavy loads. Not like anything about our fetish is realistic. Well, other than the "breasts can swell as much as 25%" thing.
©Punchy
P.S. This was done in Krea-2 with no LoRAs. Just straight-up Krea-2 with the node that rebalances the conditioning so it doesn't censor as much.