Isis is an Egyptian god. (not the terrorist)
She loved Osiris and got married. (Happy ending right? No)
The gave birth to a son. (Very Lively, his name was Horus)
But then, Osiris was cast into the underworld and was made god of the underworld (Oh no!)
Isis was sad, then she got some crazy idea to marry her son (wait what?)
She then decided to fall in love with someone else (Horus was mad)
So Horus killed the guy (what? No wonder the guy is the god of war)
So then Isis fell in love with another guy and Horus gave up (This is sad)
Meanwhile, Osiris sat in the underworld, thinking of his wife (the end)
She never wanted to marry her son and you are leaving out Set or Seth depending on which translation of his name you go by. You are also leaving out the whole coffin thing, the tears of Isis, and Horus training to avenge his father and losing his eye, hence why Ancient Egyptians would carry around a necklace in the shape of an eye. Also, Isis has always been faithful to Osiris in the myths.
Isis is an Egyptian god. (not the terrorist)
She loved Osiris and got married. (Happy ending right? No)
The gave birth to a son. (Very Lively, his name was Horus)
But then, Osiris was cast into the underworld and was made god of the underworld (Oh no!)
Isis was sad, then she got some crazy idea to marry her son (wait what?)
She then decided to fall in love with someone else (Horus was mad)
So Horus killed the guy (what? No wonder the guy is the god of war)
So then Isis fell in love with another guy and Horus gave up (This is sad)
Meanwhile, Osiris sat in the underworld, thinking of his wife (the end)