Yeah, the agency one is likely 99% certain it was a sexual scandal given the hints about MinJee's past.
Although given she's been dating Daeshim since high school that leaves her a small margin of time for having dated Liam unless she was fucking since like 13 (which is very possible in today's day and age) since that would mean she likely started dating Dae between 15-17 years of age most likely. IIRC she pretty much tries to evade the question of when did she date Liam/why Daeshim didn't know about him, so although its very vague there is the possibility she was two timing when she start dating Dae but then broke up with him and became exclusive to Dae (or at least tried to, would be more accurate).
NTRman really needs to clear up shit like this, I love "read between the lines" type of things, but I love them when they're things that are pretty much indirect/borderline confirmations for those who pay attention, not when they're just "could be this or could be 10 other different things, make of it what you will" which just leaves us with the doubt lol.
This is my interpretation
Most of my interpretation is base on the question Minjee asks Dae so...this is what I think
-Regarding Minjee's past, yes I think that she dated Liam when around 13-17 bc there was a line Liam said you(Minjee) are a bit bigger than the last time I saw you
ps. I asked my friends when he had his first time he said 14 so..it possible
-About two timing I believe that it's possible but I'm not giving that theory too much value, I think she broke up with Liam before starting dating Daeshim in High school. There also a question she asks Dae that Is he believes in love at first sight, I think that means Dae
Why she got Kick out of K-pop agency and the past with Liam The theories that I can think of are
-When Dae fuck Minjee for 3rd? time she strongly insisted not to take sex video like she had a past with it.
-There a question that she asks "as how Dae thinks about open relationships", This line I think it means Liam was a playboy while dating her he also dating others too so when Dae answer that "mutual agreement is a must" she liked that
-There is also question that "Do you think there's different between emotional and physical infidelity">This supports above that Liam is cheating on her so she asks us to check that is she the weird one to thought it weird
So this are the Theory
-1. she was dating Liam when she is k-pop trainee and Liam cheated on Minjee. >Liam wanted to record sex video Minjee agree somehow> Liam bragging to his friend and the video got leaked so agency kick Minjee out
So This is why she hated sex taping
-.2she was dating Liam when she is k-pop trainee and Liam cheated on Minjee >Liam want to record sex video and she quite uncomfortable with it, so she consulted with her friends >but it turned out that her friends want to destroy her career her friends leaked the video and she got kick out
-3. she was dating Liam when she is k-pop trainee and Liam cheated on Minjee ,> so she consulted it with her friends somehow her friends suggest revenge by taking video of her cheating on Liam with another guy> it turned out that her friends want to destroy her career her friends leaked the video and she got kick out
-and after all that she fall in love at first sight with Dae
this support by question "would you call your friends to discuss it or try to sort thing out with me?"> bc she got betrayed by her friends or Liam got video leaked bc his friends
and also question "If I told you that I have cheated on my ex, would that make a difference between us?" > she want to test Dae that if he will hate her or not
This theory leaning on Minjee side but I believe it's the most possible one from my pov
About Liam's route why Minjee easily cheat on Dae?...you know it ntr part of the game so it might be quite fast