My Covenant with the Monster Lord

Yu Yin died, only to be reborn in the 21st century and transmigrate twenty years after his death. Upon returning to his original cultivation world, he was "Deceived" by Bei Xiao, a Demon Lord he did not know. Not only was he deceived, but he was also bitten and forced into an engagement! While Yu Yin was left stunned, the Demon Lord treated the situation as a matter of course and refused to let him go.
Bei Xiao: "Now that you've found me, you have to take responsibility."
Lost memories and a fated reunion.
Bei Xiao: "We’re already so close; why won't you let me pester you?"
Yu Yin: "...You don't have to do that."