Why are you so sure that Marinette doesn't have any feelings 4 u?
You already have mentioned that is bc she's always calling you her best friend but u r doing that too
And she's your best friend, you know how she is about stuff that get her nervous
Maybe she doesn't think you like her that way or just doesn't want to get her hopes up
What would you do if somehow she finds out your feelings, and hypothetically confess that she feels the same, you'll have to live with the fact that you were hurting her and yourself for a long time because non of you confessed?
Oh, and how do you about privacy respect in relationships? Couples can have secrets? Not for lack of trust but for respect?