Your new girlfriend leaves you at her house and goes out on business, and before she does shows you the bottle and forbids you to touch it!
But the guy( you) is very curious and drinks the liquid from the bottle turning into a very small, and learns a lot of interesting things about his new girlfriend, she show her big belly, big tits, she stay on bed on wich you have sex with her- she is very happy see you small

Vore/Giantess/Belly fetish