@BryTheGuy it’s always a highlight of stories when I find it, too! They’re just so damn tiny!
I need to look at an actual science textbook to figure out how small the tiny would actually have to be to be able to see sperm with their naked eyes. I usually imagine the sperm as tadpole-sized to the shrinkee- still small enough to swim up their cunt in a terrifying parasite-like swarm. It adds to the fear play in my fantasies.