Nahh, this is actually my first time playing the game. I downloaded it recently, so I’m using a completely new save file.
So that's the end of the story that's currently in the game. After receiving the underwear from Vanya, there's a message saying the story is over for now, but you probably just clicked past it / skipped this notification
The only thing left after win her panties is to view this in 3D in the player's room while interacting with the closet.