My Players Are So Fierce - Chapter 244:

〔Congratulations, for mating with a Queen Bee you got a new achievement: ”Not a virgin”! Your reward: “Drone Consort” title.〕‘Hey! I wasn’t a virgin before this, system!’Imagine that you lived a painfully average life, died by a stupid, stupid accident, but a goddess interfered and gave you a second chance in another world.There, you became a consort of a beautiful, big-chested queen, and your only job is to have mind-blowing sex with her so she could have thousands of your adorable daughters. In return, you can live in peace and luxury for the rest of your days.Which means, for about two months. Because I’m a bee. And my queen is also a bee. And bees don’t live for long.The only way to increase my lifespan is to develop my bee colony. A hard task in this huge world filled with dangerous and hungry beasts, other war-hungry insect tribes, and natural disasters.But I have a hundred thousand daughters, some actual brains, and with superior genes given to me by my system, we will be unstoppable!===Note: no NTR, harem, incest, or outright smut.

Kaito Nakamura, a shy university nerd, thought he’d found love when the stunning Aiko chose him as her boyfriend. Their sweet, fluffy romance fills his lonely world with hope—until he discovers she’s cheating on him with multiple guys, reveling in the taboo thrill of betraying someone so innocent. Heartbroken and humiliated as explicit photos of her circulate online, Kaito’s tears are interrupted by a mysterious popup: the “Revenge NTR System Beta.” Promising retribution but with a chilling condition — he can’t break up with her.Contains Ntr, read at your own risk

Ye Xiwen was previously only an ordinary university student on Earth, but unexpectedly crossed through into the world known as the Zhen Wu Jie world! In this world, formidable warriors are capable of turning over mountains and collapsing the ocean, destroying the sky and extinguishing the earth! He originally had ordinary aptitude, because of that he received the mysterious special space! Any martial art can be deduced within the mysterious space, other people practice for decades, he only needs a year! So long as he has enough spirit stones, any talents he faces are all floating clouds!

- Description from Novelupdates

You thought being reincarnated as an extra-side character was bad? Imagine being thrown into the body of a villain who is disowned by his own family and discarded by the author.