The absolute determination in Finn’s tone was perfect. It was like “Here dude, see for yourself.”
This episode was hilarious!
Fun facts from Adventure Time Wiki:
I don’t even watch this series, but this is adorable because that’s the exact relationship John and Sherlock have, except that theirs is a little bit more hidden, a little bit more shady. But again, both Sherlocks are shady people, enlightened by their Watsons in a different, yet equal way - they were the only people who could make the Sherlocks feel a little bit less… horrible people, weird people, different people, and that’s what’s wonderful in their relationship: in the Sherlocks’s world, their Watsons are the only colorful people.
Oh, you should watch it; it’s lovely! I started out of curiosity (and my love for Lucy Liu) but got hooked pretty quickly. Also relationship-wise, they never break the original Sherlock/Watson balance - which was the concern among some fans before the series. They’re just adorable, awesome, witty, exciting and a ton of fun to follow.