Any stories where a school or college boy rapes or has consentual sex with a girl and he gets castrated in public in front of his parents.

Try using an additional search program

https://ea-tags.droppages.com/

Can't say I've read a story with that exact description, but it sounds like a great premise! Especially if said boy is well-hung and proud of it.

I've read similar stories, for example one where a boy gets nullified by his dad as punishment for doing it with his mother.