oh boy i'm not ready for THAT english translation
ANOTHER THUMBNAIL (second picture, but this may confirm chapter 66 as a flashback, since taesoo is seen smoking): https://twitter.com/nejade_/status/1022860800321449986?s=21
also, the thumbnails featured on the korean lezhin is in color on the creator's blog!
Omg..yea right I saw thar too...and I think it's not a flashback.
I read your reply as "taesoo is seen smoking hot" (▰˘◡˘▰)
Well, it wouldn't be wrong
So I checked the lezhin raws and I can't buy coins but the chapter thumbnails are visible.
The latest chapter in lezhin korea has a thumbnail where Taesoo and Ms. Doh are looking at each (I'm guessing they are in the office). It's either that scene is in past (somewhat confirming they were ex-lovers) or Taesoo and Ms. Doh will meet soon. Here's the link https://www.lezhin.com/ko/comic/snail