I am just forgetting or is there a part of the story missing between ch 19 - 20. like ch 1...

I am just forgetting or is there a part of the story missing between ch 19 - 20. like ch 19 left off on them having sex but ch 20 is a few days later talking about this "couch event" that happened that supposedly happened that night. like for the life of me up cant remember any part of the story where Hana was crying (maybe even scared) on the couch with Woo hyeon pinning him. or am I just dumb and its a poorly done intestinal plot device