Please help MEH

okay so I can't remember the title no matter how many keywords I put but the story is basically like the mc opens a portal to the demon world with his cum and so a demon that wasn't supposed to come out came out of the portal. He comes like kind of in the form of a kid and gets tired a lot and sleeps and eats a lot but he sticks with MC to take care of him. Then like he is supposed to be in the demon world since he has a fiancée that he doesn't want to marry which is why he left. The fiancée finds out about the mc and the demon and sends a demon to catch MC and well mc yells and the demon sleeping hears it and goes to the demon world to rescue him and my god is the demon got asf but yeah whatever I can't find please help (￣∇￣")