[Iris art] Mura no Okite Koibito wa Ore no Mae de Hoka no Otoko to Fuufu ni Naru | 村规 我的恋人在我的面前和别的男人成为了夫妻 [Chinese] [黑与白之间的我们]

Frankly this is not NTR at all. Historically before there were governments, every village had its own set of rules. So arranged marriages were a norm back in the days. If anything, the girl was the one that cheated, and even knowing that, the new husband said he wouldn't tell anyone, but from now on just to be his girl and no one else's, so their's no blaming the new husband. The MC is a major loser in this because the least he could have done is to go to the village chief and told that he already had a relationship with the girl and defend it. But he was a coward and deserved to get everything that happened to him. An idiot like him deserve to regret big time.