https://www.dlsite.com/maniax/work/=/product_id/RJ01224273.html
https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_406807

In this story, the childhood friend is the NTR guy. The female MC is dating someone but the female MC's boyfriend has been cheating on her...

Base +12, hentaipower938 +3, Pachris +9

这位大佬画的Ntr都超棒的。可惜只有两部有汉化

Base +6, andyfrankbloop -5

So does this count as netori?

Base +8, Pachris -9

>Mina (active for 2 years), a girl who loves her first boyfriend, is living a lovey-dovey life with him. However, an incident caused that life to fade away.
>The incident was when her boyfriend, Masato, went out with a girl friend.
>Mina wanted her boyfriend to only look at her.
>However, with his first boyfriend, she didn't know how to act, and it was her childhood friend, Sakai, who noticed her gloomy face.
>Masato suggested that she should "learn how to treat a man" so that she wouldn't look at other women, which confused Mina, but she also had a strong desire for her beloved boyfriend to only look at her...

Base +20, mirw -6, dirtyhairry +29