Robin: But how could you have gotten a trophy for a rap contest if you weren't there.....?

BB: I don't know.

BB: Ha! Gotcha! I was at a rap bar. And won a competition against Bling!

The competition didn't start yet.

(Then how come he has a trophy? Trophies are won from competitions!

Well they didn't have the competition yet. They are going to battle at the rap grand slam in a couple of weeks.

(Then he shouldn't have the trophy. Since he does, then they've already done the competition. Simple)

But they didn't have the competition yet. That's what I'm trying to get you to understand.

BB: I was doing some work.

(Then WHY DID HE HAVE A TROPHY?! You get trophies from COMPETITIONS.)