@Xuvero's review was quite interesting on the subject of their differences, but I'd like to add something to it. Tangy Mustard is, indeed, the cool one. He doesn't care what other people think and he's confident, unlike Sublo, who is awkward and insecure. We saw this when Sublo tried to draw a beard on his facehole to be cooler. This actually makes sense with their dynamic. Sublo goes along with Tangy Mustard, which is why they're so similar. Sublo is impressionable so Tangy Mustard's confidence imprints on him. At least that's my thought on the subject.
Anyways, about the actual episode. It was funny. The animation was once again pretty nice. I liked how Sublo & Tangy Mustard legit reiterated everything the other said the whole time. It wasn't just a joke you threw together. Also loved Tangy Mustard's creepy backwards speaking and the way he had to subsequently explain everything. Katy's attitude fit perfectly and I quite like Xuvero's explanation in regards to it.
Great job again, I have to watch the next episode soon! You really are talented.