Episodes Suggesting a Friendship
In A Lemony Lesson, the two worked together in the challenge, as they both dump lemons into their team's basket.
In War De Guacamole, during the baton relay race challenge, Paintbrush lands in the guacamole incorrectly and hurts themself. Afterward, Paintbrush handed the baton to Marshmallow while still under the guacamole, and also still in pain.
In Aquatic Conflict, Paintbrush is eliminated, and Marshmallow states how they don't deserve to be gone, because "he's" great. Apple points out that she thought Paintbrush was female, which Marshmallow responds unsure as to what gender they actually are Paintbrush starts to answer, but before they could respond, Paintbrush is dropped into Idiotic Island.
In Let 'Er R.I.P., Paintbrush helps Marshmallow ditch Apple, then Marshmallow explains to Paintbrush that she finds that it's annoying that Apple doesn't care about Bow, and she tells her that she feels guilty about Bow's death. Paintbrush tells her Bow would have understood as she was trying to save MePhone4 in the finale.
In Mazed & Confused, Marshmallow wanted to talk to Paintbrush in private while excaping the maze talking about her relationship with Apple. Paintbrush goes as far as to physically hurt Fan, due to the fact he was ridiculing Marshmallow, saying that she was one note.In Kick the Bucket, Paintbrush is very distressed that Marshmallow isn't present, and they demand to be told what's going on. Afterwards, they are very disappointed that Mashmallow refused to tell them where she was going.
Episodes Suggesting a Conflict
In The Snowdown, Paintbrush, Marshmallow, and Apple were standing by a warm fire. Paintbrush shouts out that Santa Claus isn't real, causing Marshmallow to yell back at Paintbrush, who only exclaims that it's true.