Bob: Kanye West.
Dad: No, but I can East.
Bob: Kanye West.
Dad: No, but I can East.
Alright listen up, genius. The joke is that the dad is making a pun. Kanye West is a famous rapper, and "West" is also a direction. The dad says he can "East," which is another direction, playing on the sound of "Kanye West". It's like, so simple even you should get it, you goofy goober.