unappreciated
Not recognized, as to quality or worth: an unappreciated gesture of good will. Taken for granted.
He feels unappreciated by her.
unappreciative
Not valuing something, In particularly from past situation.
My sister was very unappreciative after all the stuff I bought her, I felt as though I was more betrayed than hurt.
Unappreciated Rejection
When the friend of someone who is about to or just entered into a new relationship gives their approval or rejection of the partner but is completely ignored by the person and still goes on with the relationship.
Person 1: "So when do I get to meet her?"
Person 2: "Soon why?"
Person 1: "So I can give my unappreciated rejection, we both know you're gonna get with her anyway, I just gotta let you know what I think of her"
Person 2: "Soon why?"
Person 1: "So I can give my unappreciated rejection, we both know you're gonna get with her anyway, I just gotta let you know what I think of her"