In such instances, you will find your partner slipping out about their promotion or even going on a trip with their friends, the very next day! You will probably be the last person to know about their major life events, and that too, because it accidentally slipped out of their mouth. They just don’t see you as a person important enough to tell the news.
Prioritising someone requires work, effort and time. If the person values you enough, they will never take you for granted nor will ever keep you in the dark about their actual feelings.