MTL - I Really Don’t Know How To Practice - Chapter 899 clearly stated

Lin Mu is the number one genius of Jade Sect—handsome, elegant, and peerless in cultivation. Revered by elders and envied by peers, he stands at the top in every way… except the one that matters most to his lovers.He is small. Quick. Weak. In bed, he’s a failure.And everyone in the sect knows it.Women fall for his charm, only to leave his bed aching and unsatisfied. His first wife, Xue Lan, still loves him—but seeks her pleasure in the arms of others. Soon, more women join him, enchanted by his beauty and tenderness, only to find satisfaction in stronger, rougher men......WARNING: [Netorase], [Cuck], [Cuckold], [Netorare], [SPH], [Size Comparison]

A data loving young man from Earth has an accident which transports him to a dark land filled with terrifying creatures and magical powers. Fortunately for him, he has a Biological Assistance Chip to ease his path. However, things in this bizarre and strange world are not always as they seem, and, though it is a tremendous asset, the chip doesn’t always work as expected. With all of the crazy creatures and magical mayhem around him, one can only wonder what the future holds for this young man…

Two years ago, the mere fifteen-year-old scion of the Lin family, in front of the colossal behemoth that is the Murong clan, made a vow!Two years later, no one knows what he has gone through, but from the moment of his return, he radiates a brilliance that seems to compete with heaven and earth!(Note: The protagonist of this book is very aloof, cold, and passionate. Those who like to read about a military king's ambiguous romances and flirts, please bypass this one.)

Within the virtual world of “Avalon Online”, Finn, or otherwise known as “Echo” within the game, was one of its greatest players. After logging off from a long session, however, he notices something awry outside of his apartment.The streets were flooded with chaos, screams echo through the night, and hell is loot loose. Monsters from Avalon Online are running through the streets, wrecking havoc. In the midst of this hellish awakening, Finn is greeted with the one gift bestowed to humanity in this dark hour:[...Assessing life experience…][Assessment Complete][Name: Finn Thorne][Age: 20][Designated Class: Assassin][Starting Level: 5][A [Legacy System] has been bestowed to you for your accomplishments within Avalon.][Assimilation System Awakened.]In this twisted turn, as the world as it was once known is gone with the arrival of magic and monsters, the remnants of humanity must level up if they wish to survive.Finn is left in this dark, hopeless apocalypse, using his own experience from Avalon Online to best survive what seems to be an impossible task.