Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 309

A high-ranking officer in the Marines and a master of both Western and Chinese medicine, Feng Yu Heng is transmigrated with a duang sound to the Da Shun Dynasty.

As a walk-on, he had been the mistress of his sugar daddy for three year. However, they only had met each other for a few times.
As a boss, his sugar daddy had tons of lovers.
The walk-on: The cake shop is the only thing I love in this world. Lovers? Never want one.
The boss: No problem. Nobody wants that.
Then, they fell in love with each other…
Shameless playboy x heartless rogue
1v1, this is not a decent love novel.

- Description from Novelupdates

Cao Xin, a young man on earth, died in a car accident, traveled to a troubled world where supplies were scarce, and obtained a “Bronze Immortal Gate”…

…

- Description from novelbuddy

The year he was fifteen, Ling Ke realized he was gay, and that he fell in love with a hot guy the same gender he was! Ling Ke spied on the other’s online friend group, payed attention to that person’s every move, and privately, started his fanatical fanboying actions. Unfortunately, the hot guy he liked was someone who changed girlfriends like he changed clothes, a pretentious and straight male.

A few years later, Ling Ke and the hot guy he was secretly in love with got into the same university and became good friends. In order to prevent his beloved from hating him, Ling Ke repressed his true feelings and forced himself to pretend to be a 24k, pure gold straight guy.
……

Having high-spec looks, Qi Feng was a networking expert, but in order to preserve his all-around shining and popular hearthrob image, he always hid his true sexuality, that he was gay. He got himself (fake) girlfriends all throughout school, literally playing himself into being branded as a skirt-chaser.

Until one day, he met his true love. The other looked delicate and gentle, cold and out-of-reach, as if the ideal lover he’d dreamed of in his heart.

Except, there was just one thing. That guy also looked completely straight……

In short, this is the love story of two scared, in-the-closet gay guys pretending to be straight while mutually trying to feel the other out.

- Description from Novelupdates