How old is your son?Same my mother always doesn't mind I'm there or my relatives and my friends are present when she was change her uper dress aur bathed.
Now my wife change her dressed infront of our son or she come out topless from bathroom after bathing and our son is there. Even my wife talks with our son with her exposed breasts and our son stare his mother's breasts and it is normal in my house and in our culture.
Even my wife knows that her son fantasizes about her she didn't change her living styles.