I don't usually write for this ship but I love them so I'm going to try.

Jungkook is hurt because taehyung lied to him after sharing an intimate moment together.he goes to Jimin crying and in his heartbroken state asks Jimin to be his fake boyfriend to make tae jealous knowing very well that Jimin has feelings for him, but he doesn't see how messed up this is because he's only thinking about taes feelings as he just wants to make tae jealous by using Jimin since the younger knows about taes one sided crush on Jimin. 

Bear with me this is a bunch or hurt and maybe has a happy ending