>>11317073>>11317191I remember reading this very book as a kid and my whole body feeling hot and being hard as fuck. I dont remember that ending, but I do recall there was a sort of slow shrink part near the start and then also the element of a younger female cousin that flipped some switches that had already been lining up from various 90s media. I actually much prefer giantess content when it comes purely to rubbin one out, but I really just love the imagery of tiny girls and them in peril/needing to be cared for. Also just always liked the idea of a tiny female companion, be it a fairy or whatever. Also as mentioned by others here, the scenario of older tiny and younger big is great.
There was actually another shrink based Goosebumps CYOA book and for years i had searched for it, but it was kinda a let down. Theres a section with the character shrinking out of their clothes in their house and later on hugging the ankle of a neighbor girl to get their attention, but thats all that stood out to me. The premise i saw online for it made it sound like it was about two girls shrinking the main character.