Peachauline

Peachauline is the femslash ship between Pauline and Princess Peach from the Mario series.

Canon
Pauline was Mario's original love interest before Peach was introduced as her replacement. In spite of they are the "official" love interests in the series, both have yet to meet in the upcoming series game Super Mario Odyssey.

Although they've never interacted before, they have some similarities: they're both authority figures, both were/are Mario's love interests, and while Peach is wearing a wedding dress, Pauline's mayor attire is a suit.

Fanon
Though Peach and Pauline respectively have older game appearances before Super Mario Odyssey, Peachauline actually is quite a new and well-received ship in the fanbase due to their similarities and both characters will first time appear together in said game since Pauline was first revealed to be returning.

Trivia

 * Actually Peachauline is a pretty popular Mario ship in Tumblr.