He didn't want her to know that he had now become an underling of the godfather, nor did he want her to know that he had gotten himself involved in drugs. The absolutely impermissible thing for her to know was that he had become involved in drug trafficking.
Her sense of morality was very strong; she would never tolerate him doing such appalling acts.
She also detested the godfather deeply and could not stand that he had become a drug trafficker under the godfather, turning into the godfather's henchman.
If she knew everything, she would definitely show a look of astonishment and disbelief, hate him, look down on him, unable to accept her.
Although this day would inevitably come, he still felt heartbroken and hoped that this day could come later, allowing her to be the last to know the truth.
