No such thing as separation
Dazai and Chuuya have been secretly married since 18. Now, in honor of the truce between their organizations, they make a big show out of messing with their colleagues while subtly, or not-so-subtly, revealing their relationship. Also: They're disgustingly in love.
Or:3 times Soukoku had the time of their lives messing with their co-workers and the one time they finally told them they were married.