Does he understand the function of therapy? This is a really naïve thing for him to ask. Friendship isn't therapy. And how can he know your internal world better than you know it yourself? He seems very confident about dismissing your experience, where is his curiosity?

For me, my young aspect is far more than a manifestation of my attachment wound. She is also playful, brave, creative. She can be hurt, wrongfooted, ignored. She is alone but she will seek out love, sometimes.

He is missing large parts of your character by not taking the time to look at your child and what you are bringing to the relationship with him.