Maybe before his turn to the dark side, Anakin mentioned to Obi-Wan that he and his wife were trying to have children, and he said “You know, I’d like my son to have my lightsaber when he’s old enough.” Again, since we’re ignoring the prequels, the backstory implied in the OT could have Jedis that don’t forbid romantic love. There’s nothing in the original trilogy that says Anakin never knew he had children until after they were born, just that he didn’t know he had a daughter.
They were both hidden:
“To protect you both from the Emperor, you were hidden from your father when you were born. The Emperor knew, as I did. If Anakin were to have any offspring, they would be a threat to him. That is the reason why your sister remains safely anonymous.”