My Boyfriend Sunflower

I picked up a handsome little brother who was injured, but I didn't expect that he turned out to be a monster. He smiled and said: "Then... The grace of saving my life should be promised with my body. If I marry you, I can be with you!" I was not allowed to be a demon slayer and was not allowed to get close to monsters, but my grandma said that monsters have good and bad qualities just like people, so I decided to save him. But he didn't seem to need me because of his injury, but the beauty fascinated my mind, so I took him home. Let me tell you quietly that my grandma is also a monster. Grandma told me herself, so I am not afraid of it. Because my parents are missing, as the only daughter, I have to uncover the truth, but what should I do if I don't know anything? Act first and then talk! I really didn't expect that a monster like him could use the skills of a human mage without relying on a magic staff! But - what I didn't expect was... He seemed to be the murderer of my parents. What do I do! I have to ask grandpa, but where has grandpa gone? Where can I find him?