Drama without love triangle 2018

What’s Wrong With Secretary Kim

• Come and Hug Me - there's a jealous SFL and a protective adopted brother, but no real love triangle
• Are You Human Too? - the ML is a robot impersonating a real person who is in a coma, and that person has a fiancee if I remember correctly but the overall dynamic isn't love triangle-y as far as I remember

Also in The Eternal Love 2 the ML is in a love triangle with the FL and an alternate timeline version of himself and they become one person later on anyway, so not a typical love triangle. 

In addition:

• Devilish Joy | Nvm, I remembered that it has a love triangle during the first portion of the drama. It's slight, but it's there D:
• Mother | though the romance is a small sub-plot. 
• The Beauty Inside