Why is the idea of being “too small” to be allowed to cum so hot?

Definitely some like psychology stuff going on, but just the idea of having a girl whom I have a crush on giggling and telling me I can’t cum and reminding me my virgin cock is just a bit too little to be allowed to cum is so hot… like… it’s so humiliating and it definitely has something to do with the fact I’m still a virgin… and my chastity enjoyment probably feeds into it too…