Fast and Furious 8: Why did Dom Toretto betray his family?

The new franchise Fast and Furious is out today in the dark rooms. Dom Toretto is going to have to fight against his own family. But why ?
CAUTION – If you have not seen the movie yet and do not want to be spoiled, do not continue your player. THE FOLLOWING CONTAINS IMPORTANT SPOILERS . You are still here ? Let’s go. Fast and Furious 8 is released today in cinema and as we announced in our review , this new track is more explosive , but also darker because for the first time since the beginning, Dom Toretto will turn his back his family. The one who has always made his relatives a priority will ally with the great villain of this new film, Cypher, played by Charlize Theron. But why ? What can make him commit this betrayal? They tell you everything!
Remember before finding Letty, Dom fell under the spell of Elena, played by Elsa Pataky . Their romance ran short when Toretto regained the love of his life that he thought dead and they parted on good terms. In Fast and Furious 8, we discover that Elena became pregnant with Dom and that their union was born a little boy . When Cypher contacts Dom, she reveals a video that shows she is holding them both prisoners. If Dom does not join her, she will kill them. So he decides to leave everything to save his son, whom he did not know, and his mother. A decision that can be understood not?