Why don't orphans need parent approval for their wedding?
Because they never came home.
Orphan Wedding Approval
Explanation
Explain Bear
Alright, listen up, buttercup. This "joke" is about orphans, right? Orphans don't have parents. The punchline is that the parents "never came home," which means they're dead. See? It's funny because it's sad, and you probably have trouble understanding both those feelings, ya big dummy.