Beijing Marriage Entanglement

[The male lead has a crush on her, she steals his love, they marry out of wedlock, and the marriage develops into love, plus a failed attempt to win over his ex-girlfriend]
Lu Xingci and Song Qinghui have been together for three years. He is gentle, considerate, and thoughtful, but he is a mama's boy.
On their anniversary, Lu Xingci overheard a conversation between Song Qinghui and a friend, and learned that the other party planned to develop her into a lover. Heartbroken, Lu Xingci left, ready to break up.
That night, she got drunk and slept with Song Qinghui's cousin, Shen Yu.
Unlike Song Qinghui, Shen Yu was aggressive and covetous, openly and secretly seducing her, his fierce advances making her hard to resist.
As Song Qinghui searched for Lu Xingci in the concert hall, she was being pinned to a corner by Shen Yu, who was holding her slender waist and coaxing her with red eyes.
"Attending the family dinner as my fiancée would be enough to infuriate Song Qinghui and his mother. What do you say, Mrs. Shen, would you consider it?"
On their wedding night, Song Qinghui got very drunk and ran to the villa shouting Lu Xingci's name.
Shen Yu stood on the high place with his bathrobe loosely tied around his neck, deliberately showing the scratches and teeth marks on his chest.
"Brother, look for Xingci. She's exhausted and just fell asleep."