Great grandma, who is this Uncle?

Stella peeled apples for her grandmother and talk about her life abroad for the past six years. Especially, the time when she was in France when Adrian was still young... Stella didn't have the time to bring Adrian home and meet her grandmother. That's why Her grandma only know that she had a child but he had never seen him or met him... "Stella... He is so cute. I am sure he is the cutest child in the world..." Grace looked at Adrian's picture on Stella's mobile and praised him. But after thinking for a while, she asked from a heavy heart... "Stella, look child is already five years old... But you still didn't tell me about who is child's biological father..." Stella's hand, holding an apple paused... Except for Emily, Stella had never talked with anyone about Adrian's biological father, not even her grandmother... Now they are already divorced and that man was about to get married to someone else... She felt like it was even more unnecessary... Stella didn't want to talk about him. S