The young woman relishes the wonderful feeling of the hot water on her nude body. She rubs her belly and her breasts, moaning pleasantly. She closes her eyes and keeps rubbing. She frowns, her breasts feel more buoyant, maybe even bigger. She shrugs, and keeps her eyes closed. She keeps rubbing and massaging her breasts, then, she works her way toward her belly.
Her hands hit a couple of bumps. Large bumps, and very sensitive. With a start, the young woman opens her eyes and sits up in the tub. Cupped in her hands are two large breasts under her old, but now gloriously big breasts. Taking her hands away, the young woman sees that she has grown two more pair of breasts, each smaller than the one above. Her original breasts have swelled up to almost volleyball-size.
The young woman isn't sure what's happened, but she isn't complaining. For the moment.