What did one orphan say to the other orphan?
"Get in the Batmobile, Robin!"
Listen up, buttercup. You know Batman, right? He's got that sweet ride, the Batmobile. And Robin? That's his sidekick. Orphans are kids without parents. So, the joke is that one orphan is telling the other to get in the Batmobile and calling him Robin, like they're Batman and Robin because they don't have parents either.