They were never mother and son biologically speaking. The father is older than her too. He is probably be 4-5/6 years older. Ain is how old? 12-14 by now. She should be in her 20s. The boy doesn't really see her as his mother. It is probably the way he was raised. As he gets older he will see that his affection is different.
The father never cared for her. He is now curious and wants to see what love thanks to his son.
Sorry can't see to what u are replying but by the title.. im guessing you are replying to that.