You Mistook Me for Your Kid's Dad? Marry Your Brother-in-Law Instead, and Don't Go Crazy

[Romance with a female and male lead. The heroine was once the hero's younger brother's girlfriend.] Four years ago, Ying Xiao was a substitute for the second young master of the Jin family’s ideal woman. She was hopelessly in love with him and followed him around all day, acting like a shameless lapdog. She came from the countryside and was at the very bottom of A City's glittering high society. “With that face, do you really think I could like her? She's just a plaything.” The second young master Jin said it with cold disdain. All the young masters and ladies of A City looked down on her, and any of them could humiliate her. But she was happy to put up with it. No matter how he treated her, she remained devoted to him. After disappearing for four years, Ying Xiao showed up again. When she returned, eyes red from crying, and begged the second young master Jin to let her stay, no one was surprised, including him. After all, Ying Xiao was hopelessly in love with him. - Jin Si was the head of the Jin Group. He was disciplined, courteous, and dignified, and never let a woman get close to him. Everyone knew he was abstinent and restrained. Some even said he liked men. He had heard a little about his younger brother's scandalous love life. Especially the country girl who had turned A City's high society upside down four years ago. After a few years of peace, she was back. His reformed younger brother had become willful, violent, and irritable again. “Ying Xiao, how can you be so shameless? You betrayed me four years ago, and now you dare flirt with other men? Who is that bastard, anyway? Is he the father of that little bastard?” Jin Si felt a surge of displeasure. Then he heard a somewhat familiar voice speaking ingratiatingly to his foolish younger brother. “Ah Chang, I love you most. Please believe me, okay? I really don't have another man. Don't stop loving me. Don't send me away, okay?” Jin Si whipped around. The delicate woman who had begged him to go slower just last night was now straining to reach up and kiss his foolish younger brother.