It reminds me ages ago of a fan art done of "Pokeranger" That depicted a girl similar to misty who was swimming iwth her bottoms off, where a Barboach swam up her happy hole, wiggling around. She tried grabbing it by the tail to yank it out where she pleaded with it to stop moving and told him "Don't you dare evolve!"
I'm going to go out on a limb and assume wild Pokémon can do that? So some deranged trainer has ordered there Pokémon to do it. I knew the Pokémon universe was fucked up as hell but this takes the cake