I reported a co worker that has a crush on a student? Did I do the right thing?

She told me two weeks ago after work and I told her, "Are you crazy?! That's a 13 year old boy! You're 26. Gross. Get that out of your head right now! What's wrong with you?!" How disgusting was that! She said he's cute and gave her a compliment and her boyfriend treats her like *kitten*.
I called her out for it. She told me not to tell anyone a out her crush. I reported it to the bosw but he scolded at me for "tattletaling" and it might of been a misunderstanding. He told me if it happens again, I'm fired. But she has a crush on him and I'm afraid something will happen. I dont want nothing happening to that 13 year old kid.