I think Lawyer Ahn Dantae is Joonpyo
Dantae spots Joonsoo continuing to act suspiciously. He loses his trust in Joonsoo and suffers from the thought of not being able to be friends like they once were. Meanwhile, Joonsoo waits for the results of Dantae's DNA test convicted that Dantae is Joonpyo. With this, he proposes something to Taecheol.