Is it a sin if you accidentally saw your mom nude?

the chances are when you where younger your mam might have took you in with bath with her for ease. This lady is your mom, why would there be any harm.

What makes us think any relations between Mom and Son, or any other Incestous Taboos should be considered a sin, while in the holy Bible, Indirectly, we hear about it...

How Human had to survive and increase the population, If he was forbidden by a very close god? Weren't Adam and Eve the closest EVER! Human beings to god? He could only tell about the Apples? or we must consider the Apples the Taboos??