Inspired by post by @5unny-lmao
Pre-movie 1 Robotnik had a James Bond movie binge and of course he wants to join in on the classic "villain with a kitty-cat in his lap" trope (he also does the whole dramatic chair spin). Actual cats are obviously over-rated and would shed all over his lab, thus Stone gets that role. Rob enjoys the discomfort that this greeting pose causes in any uninvited major nobody-careses/Walters when they visit, so it sticks for quite a while.
Poor Stone is just trying his best not to cum die of happiness in his lap.
Version without speech bubble below cut.















