Caught my LDR cheating on Snapchat right before his birthday how should I reveal that I know?

I’ve been in an LDR with this guy for a long time, and recently I had this really strong feeling that something wasn’t right. He kept telling me he barely/never uses Snapchat, but I noticed things that weren’t adding up.
So I made another Snapchat account and added him without him knowing it was me. And yep… my gut feeling was right. He actually interacted with the account and basically proved he’s been lying to me. 🙃
The funniest/worst part is his birthday is coming up soon, and he still has NO idea that I know.
I’m obviously done with him, but now I’m debating how to reveal it. 😭
Option 1: Send him a birthday cake with something like “Happy Birthday, Cheater 🎂**”** written on it and then disappear.
Option 2: Send him a normal Snapchat streak from the account he doesn’t know is me, but make the snap a picture of ME so he suddenly realises who he’s actually been talking/snapping to. 💀 Then remove/block him without explaining anything.
Part of me thinks the Snapchat reveal would be way more satisfying because I want to see the moment he realises he literally exposed himself to his own girlfriend.
What would you do? Cake, Snapchat reveal, or just block him and say absolutely nothing? I want something petty/funny, not anything illegal or genuinely harmful. 😂