The ending ruins it for me with her being such an awful person, but ah well Yuni's art is always absurdly hot regardless.
I mean the bad vibes were constantly farting out of her mouth, "You're mature for someone so young" my goodness it would be much more upsetting if she was a good loving senpai
She had varied red flags sure, I'm not saying her personality at the end is out of the blue or that she should be a good person, only that her blatant player behavior at the end was off putting for me personally.
This is just my take on her behavior (and I forgot her name) but it feels like the woman with glasses entered a relationship with her partner mainly to distract herself from her feelings for her boss. That's why she makes those overly flirtatious jokes to her boss right in front of her current girlfriend. When the boss shuts it down by mentioning how much she loves her husband and kids, the look on the glasses lady's face says it all, she's completely irritated that her flirting tactics aren't working. Pretty neat how much you can get out of a short two chapter work.
I think Itou's primary feelings are for the married woman she can't be with, and because she can't be with her Itou spends her time fucking varied woman that are pulled in by her charms as a means of venting. Unfortunately Tsukishima was caught up in this and things will only end badly, as it's been said Tsukishima definitely deserves better.