MTL - I Was a Group Pet In 80 - Chapter 1577

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

Probably Shy Loyal Dog Gong X Slightly Blackbelly Used Goods Shou

When a new neighbor moves in across from Chen Xiao, he sets his sights on the handsome young man, Gu MengYang. Though he’s coming off a bad breakup, he still wants to find love with a new man and wants to bully that man along the way!

Meanwhile, his fellow blackbelly friend from childhood, Luo Xin, noses in to “help” him catch his man. And, behind the scenes, tries to find a love of his own.