Japanese by Example
Learning through examples in manga

To end up betraying with 〜ことになる

レンタルおにいちゃん » Volume 3 » Page 120

Makoto explains to Misuzu that he’s been looking into various things since meeting Kanami, such as housing for orphans. However, he realizes what Kanami wishes for is to have her once-kind brother back to the way he used to be.

"If I separate her from him..."
(かな)()ちゃんを(きず)つけて…… 裏切(うらぎ)ことになる
"...I'd be hurting Kanami... I'd end up betraying her."