Oh I see where you are coming from now. Thing is, I'm of the impression that she just wanted a break which is just time off. I know it was sorta implied that she was considering what would happen if they were to part, I dont think it meant that she was going to leave him (not necessarily right then at least).
He does deserve an explanation but my point is, it's not easy to talk about a trauma so if she isnt ready, she doesnt have to talk about it straight away (to fix their current predicament) which is what I thought you implied.
But I do think I might have gotten carried away cause I thought you made light of her trauma.
"And from such a little trigger at that". When suffering from PTSD, it is such little triggers that can make you spiral into these kind of feelings and thoughts. What's little for you is not little for someone who has severe traumatic experiences. You don't "let your demons get you" - it's not a choice. Have some empathy.

That not so subtle cameo from Raising a bat tho ♡♡♡
Now, wth is the author planning? this is the worst timing for Sooha to let her demons get her. And from such a little trigger at that =_= I hope she properly talks to Taesoo bc he doesn't deserve another gf who takes it out on him.