The Ending Is so Cool That I Can't Read It

I want to read a book like "Mr. Gu, stop pretending, your wife has already married someone else and is pregnant". When the wedding was approaching, she found out that her fiancé was going to marry her sister who had just returned from abroad. Frustrated, she turned around drunk and went to get the certificate with someone else, but she didn't expect that the other person had a crush on her.