If this is how you feel, you could just thank him and say that you're glad to be in his workshop as well. Personally, I would assume he would ask to read them if he wanted to/had the time to, but maybe he's hoping you'll offer them up? What's the etiquette on asking to read someone's writing? Were these stories you worked on previously in his writing workshop that he might have already read? I don't think there's anything boastful about sending him your stories whether he's read them before or not. You should be proud!