Nobody is going to fault you if you think that Mario and Peach are together romantically. In fact, I’m not going to fault you if you think that Mario has a thing for his earliest “love interest” Pauline. After all, he does spend a good deal of time saving Princess Peach, and initially, Pauline.
However, we all could not be so wrong. In the latest “Send Your Letters to Mario”, Mario flips out of the romantic scene and friend zones both Princess Peach and Pauline.
In the video you can clearly hear him say:
“My friends are the best, number one! I love my friend Toad, and Talkatoo, and PRINCESS PEACH, and PAULINE, and Cappy…”
Looks like it is either both of them really are just friends, or Mario has a lot to explain to the Mushroom Kingdom’s monarch when he is off-cam. In any case, you can definitely write in to Mario at Mario@noa.nintendo.com to clarify, maybe he will entertain your questions in the next episode of “Send Your Letters To Mario”