The wrong apartment

Take Nguyen's part first, then Amara's. Keep it quiet and quick, as if you're talking under loud music. Let the slow realization build from "And the door we came through said..." to "4B. Oh no."

1. NguyenGreat music. Very loud. Which one is your friend Jess?
2. AmaraI can't see her yet. There must be fifty people here.
3. NguyenShould we mingle? I'll talk to the guy by the snacks.
4. AmaraGood idea. I'll find Jess and come back.
5. NguyenAmara, wait. Who's Kevin? Everyone keeps saying happy birthday, Kevin.
6. AmaraI don't know. Jess said it was her housewarming party.
7. NguyenThere's a big cake over there. It says "Happy Thirtieth, Kevin."
8. AmaraThat's strange. Let me check her message. Apartment 4D.
9. NguyenAnd the door we came through said...
10. Amara4B. Oh no. We've been at a stranger's party for twenty minutes.
11. NguyenI've already had two slices of pizza. And I signed the birthday card.
12. AmaraYou signed his card?
13. NguyenEveryone was signing it. I didn't want to be rude.
14. AmaraOkay. Let's leave quietly before anyone asks who we are.
15. NguyenToo late. Kevin is coming this way.
16. AmaraHi, Kevin, happy birthday. We're so sorry. We showed up at the wrong apartment.
17. NguyenWe're looking for 4D. A housewarming.
18. AmaraOh, you know Jess? And you're all going up there later? The more the merrier, then.
19. NguyenSo now we're bringing Kevin's whole party to Jess's party.
20. AmaraJess will either love us or never invite us again.