LTNS

-sexless married couple who tried to find spark again
-involved cheating
-genre wise is not similar but the main point is similar

Both drama discussed the same issue, to fix and improve their sex life. However both of them used different approach to talk about it.

Both of these comedy dramas focus on a main character (or both, in the case of LTNS) who run a business of exposing cheating/infidelity.