People being surprised to see Rick and Jerry hanging out watching tv together in the after credit scene is very surprising to me because I feel like it's obvious they've been friends for ages now.
Like it was evident that they actually get along really well, even all the way back in S3.
Like in "The Whirly Dirly Conspiracy", at the start of the episode, Rick and Jerry seem to genuinely be having a good time hanging out and drinking with each other. (Here's a post talkimg more about that)
Hell, Rick even apologizes. Which is major for Rick; especially S3 Rick. (I'm always genuinely shocked by him giving Jerry a genuine apology)
In "Bethic Twinstinct", Rick says that he installed Jerry's pillbug protocal when he got drunk with Jerry. Implying that he does spent time just hanging out with Jerry and drinking.
For goodnees sake, barely 5 seconds later, Rick reveals that he has a tatoo of him and Jerry on his ass.
In "Final Desmithation", Rick literally saves Jerry just because he cares. He gave up the power to literally control fate; but instead he chose to help Jerry.
Even Rick himself admits he had nothing to gain by helping Jerry.
And don't get me started on "The Jerrick Trap", which is basically the king of Jerry Rick episodes.
The entire episode is literally about how if Jerry and Rick put their differences aside, they would be best friends.
Morty even outright says that Rick and Jerry have a much deeper bond than either of them are willing to acknowledge.
In conclusion, Rick and Jerry have been friends for ages now; so it ain't surprising at all that sometimes they have a guys' movie night together.
