8 yr old Daughter has a boy that likes her

My 8 yr old daughter has a boy that likes her, his mom has told me about him waking her up at night to ask if she had seen my daughter, writing her love letters which so far he hasn't delivered, he has even asked my daughter to kiss him. I honestly didn't think it would start this early. I realize yes it will blow over. On the other hand my daughter has not started liking boys, she thinks boys and kissing are disgusting 😬🤷🏻‍♀️😂. My biggest worry is she may say something that will hurt him because she really has no idea that he likes her. I'm not sure if I should explain it to her and let her know it's just fine to not like him in return but to be nice and just say no. Should I say anything or just let it blow over? I feel like I should know this but apparently not. If anyone had been through this please let me know what you done!