Wife who didn't want to be intimate with her husband vs. Husband who had an affair with the woman next door... Who is at fault?

This article reminds me of the old Oksori.

A story was shared two days ago about a husband who, after distancing himself from the marital relationship and having an affair with the woman next door, responds with unwarranted arrogance.
 
The woman's husband claims, "Since we were sexless, we are not at fault," but an expert dismissed this by saying, "That does not justify infidelity."
 
On this day, A's complaint about her concerns with this story was shared on Lawyer Yang So-young's YouTube channel, 'Yangdamso.'
 
Mr. A gave birth to their first child after three years of marriage with her husband Mr. B.
 
Mr. A said that after giving birth to the child via difficult labor, he did not want to have a sexual relationship with his husband.
 
Mr. A focused on parenting instead, saying he would pay off the mortgage until the child grew up, working hard while sacrificing what he wanted to eat and do.

Then, as a couple moved into the house next door, a crisis struck their family.
 
Mr. A said, "The house next door also had a child around our child's age," and "Since our children went to the same daycare, we became close with the family next door. The two families would go on outings together and, when busy, would also take care of each other's children."
 
However, astonishingly, Mr. A's husband had an affair with the woman next door.
 
Mr. A said, "I didn't notice at all and only found out after three years," and "I left work early because it was the company's anniversary, and the woman next door was in her underwear at our house. I was so busy with work and parenting that I didn't tell my husband I might come home early, and they were doing this while I was not at home," he said angrily.
 
He said, "What makes me even angrier is my husband's behavior," and added, "We have been married for ten years, but he has shown no courtesy at all. Instead, he even told his in-laws and friends that 'my wife is sexless, so I cheated,' and he said he was the one suffering more."
 
Then she asked for advice, wondering if it was natural for a couple to have an affair if they are sexless, and whether her own fault was significant.
 
Lawyer Yang So-young pointed out that "the absence of a marital relationship for a certain period alone cannot be considered as grounds for the breakdown of the marriage."
 
He simply explained, "Fraudulent conduct constitutes a clear reason for marriage dissolution as defined by Article 840 of the Civil Act," and added, "Spouses have a duty to understand and protect each other through mutual affection and trust, and to make efforts to maintain the marriage."
 
Additionally, she advised, "While my wife was busy with childcare and repaying loans, she also experienced depression after her mother-in-law passed away. It is difficult to see the husband's behavior as an effort to help his wife through her difficulties," and "Since a sexless marriage cannot be solely attributed to the wife, infidelity cannot be justified."