You May Spank It, Once is an exploitable two-panel image series of a character viewed from behind, usually showing their buttocks. The first panel is subtitled with the character giving permission to spank them, but in the next panel, they raise their finger to gesture that they will only allow it once.

The first usage of the meme originated on November 11, 2014, when a Facebook user posted a 2-panel image of Donkey Kong, with said image using screenshots from the Donkey Kong Country TV series.

https://knowyourmeme.com/memes/you-may-spank-it-once