There might be some confusion stemming from:
* The Anime's Interpretation: The anime sometimes portrays their relationship as a bit more ambiguous and less clear-cut than the manga.
* The Live-Action Series: In the live-action series, there's a point where Tuxedo Mask temporarily chooses to focus on his "normal life" with Usagi, leaving her to face the dangers of being Sailor Moon on her own. This is *not* present in the manga or the anime.
It's important to remember that the manga is the original source material, and the anime and live-action series take liberties with the story. In the manga and the anime, Tuxedo Mask remains by Sailor Moon's side throughout the entire series, supporting her and fighting alongside her.