who's child I am?

one day I pass the room of my cousin's parents, then I overheard something that I couldn't believe it.
woman: do you think, how long he's gonna stay in this family?
man: I don't know dear, his brother still didn't tell him about that.
Woman: why he's not telling him if he's not part of this family, if his brother always keep this as a secret, when he know the truth someday, I'm afraid...
man: let's hope something not gonna happen to the both of them..
me: *silent*
next day, I keep pretending like I didn't know anything.

Notes