As far as Majel not caring, oh no, to the contrary, she cared too much. She cared so much she let him get away with it. I have never seen a woman so in love with a man as she was with Roddenberry. It must have been very painful for her to hear the stories of his relationships. She was an outstanding woman who put up with far more bullpoop than she needed to.
Well, of course, for many years Majel herself was "the other woman". She was Roddenberry's mistress while he was married to Eileen and raising his family.
Welcome to Hollywood.