https://www.dlsite.com/books/fsr/=/title_id/TITLE00271731/order/title_d/from/work.titles
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"You're so wet... Did you feel like being molested? -Beast SEX with my husband's boss over and over again..."

1-2: "I'm being molested!? ... Lies ... Fingers ..." Satomi is on her way to her husband's office on the train to deliver some documents when she gets molested.
The escalation of the act is so great that she can't take it any longer... "This man...is a chikan...! She screams, but grabs the hand of a completely different person. With the man's permission, she manages to deliver the documents to her husband... "Satomi, this is my boss, Mr. Takayama"
Her husband's boss is the man whom she had falsely accused... "I'm sure you'll be able to find a way to get a good deal on this..." Takayama's hand slowly entered my pants and started to make a squeaking sound... I should not like it but my body started to feel it... "You know what I mean, right? Youre not supposed to like it, but you can't help but feel it... "You know what I mean, don't you, ma'am...?

3: "Yeah, so come on, let's get on with it."
Her husband brings Takayama, the man who forcibly raped her, to her home.
Unfortunately, when her husband leaves the room due to a phone call from work, Takayama reveals his true nature and attacks Satomi!
With her husband on the other side of the door, Satomi feels her pussy being penetrated, much to her chagrin.
Then, after Satomi is done being fucked, Takayama pushes Satomi even harder!

4: "You're a pervert! You're feeling it all over the place!"
Satomi is reinstated to her job in her husband's department. Satomi is back at work and is assigned to her husband's department, which also means that she will be Takayama's subordinate. Takayama shows Satomi around the office, but when she is suddenly made to sit at the desk and spread her legs...

This is the other work from this author where a wife has sex with her husband's boss. I don't speak japanese, so I'm a bit confused as to why Takayama (husband's boss) raped Satomi (wife) in the first place. Was it becasue she mistakenly falsely accused him of being the one who molested her? Or what he said to her that scared her in the 3rd chapter. Nor do I know what are his intentions towards her. Is he merely enjoying having sex with her without afterthought or does he intend to take her from her husband and make her his woman? Is he a yandere?
I would really appreciate if someone who can read japanese could clarify these questions for me.

This author is severely underrated. His work is excellent, both in art and plot. Someone should comission a translation for one of his works.
If anyone can recommend a good and safe place to comission a translation, perhaps I myself will in the future.