But, it's ok to do it behind the back of a "girlfriend"???
If you can't see the hypocrisy in "I betrayed her trust", "he betrayed my trust" I'm a good guy, but he's a slime ball then I'm amazed.
We can't say it's hypocrisy. If a friend has a personal problem about his relationship with another friend, and tells me about it or ask for my advice, that can be understandable. People do this often, though you should be obviously careful when all the people know each other. Better to confide in friends that are OUTSIDE that particular group circle.
It's not about her, it's about his problem. He is not trying to use information against her, but rather is asking for help or an opinion.
Where the Japanese guy (or any guy) becomes a slime ball, is in trying to use personal information at the expense of his friend. It's like if your "friend" took e-mails from a private conversation between you both and showed it to your boss, just to get you fired. It's a despicable act and betrayal to commit harm. People kill each other for this type of thing.
Slime balls, weasels, rats, and worms (all various nicknames for this) are about selfish personal gain at the expense of others. They have no honor nor can be trusted, and if you discover a person near you is this way, better to avoid or cut them off. Such people are brokering in personal information to do harm or to steal from others. And this appears to be more prevalent in Japanese culture, than in others, from my observations.
It's hypocrisy, if TJB is doing the same thing. That is using information from private conversations with friends and betraying them in order to steal women or destroy their relationships.