Miss, Something's Wrong With You

This is the typical protagonist setting so my cheats should be coming, right! Unexpectedly, that night, my fiancée suddenly took back her words: 'I won’t annul this marriage! I want us to live and sleep together! I’ll also take care of all our living expenses! Okay, let’s do it, I have nothing to lose anyway.' After one night… Eh, there’s something a bit wrong with my fiancée?

Original Webtoon:
AC.QQ, BiliBili, KuaiKan