My boyfriend is being petty?

Here’s some annoying drama that I just need to rant and get some opinions about.

DISCLAIMER: we actually have a really mature relationship & never argue like this so idk what’s going on

So my boyfriend & have these acquaintances, let’s call them Sarah & Jake, who were dating and recently broke up. A friend of mine told me the reason they broke, because Jake wanted to drop out of college and “focus on his music.” My boyfriend asked if I knew why they broke up. I told him not to tell anyone and he said okay so I told him. While I was telling him he was literally on his phone texting his friend, Oliver, saying what I was saying. I asked who he was texting & he told me Oliver because Oliver likes Sarah apparently. He showed me what they were saying and I saw that he literally told him what I told him not to tell anyone. So of course I was pissed so I told my boyfriend I was going to text Sarah & tell her that Oliver likes her, just so he’d know what it’s like to have his trust broken. I wasn’t actually going to do that I just threatened it. I left & he texted me this

What do you guys think about this? I know it’s super silly & childish. We aren’t going to like break up over it or anything (we’ve been together happily for 2 years) I’m just kinda frustrated.

Who’s in the wrong?

My boyfriend for telling someone something right when I told him not to

Or me for responding with a petty threat

Probably both of us tbh I just want to see what others think

Update: here’s what he’s saying now