ISEKAI MAZOKU SHOUJO GA IYASOU NI SHINAGARA SHIRI WO SAWATTEKURE TO SEGANDEKURU KEN

Iyaran Kunai, a high school boy with a butt fetish, was about to be killed by a demon girl, but at the last second, he unleashes a move that’s way too lewd for her too handle!? This is a manga dedicated to ass-men everywhere— (Source: Ganma!, translated) — Description from AniList community (anilist.co).