WeHaveMoreCupsThanYou
I will get banned again soon, worry not.
That scene is similar to how the two of them became friends. Apparently they met as kids at a summer basketball camp and hated each other. All they did was fight, and not just verbally but actual fist fighting, with basketballs thrown at heads. They hated each other almost on sight. Then years later as adults they see each other at a comedy club (before either of them had achieved any sort of fame) recognized each other from the basketball camp and started fighting again.
Then, while they were hurling invective at one another one of them said something that the other one found funny and he laughed. And then they both laughed. And they were best buddies from that moment onward.