Xbooru - 2020s 2021 2boys 2d 2d (artwork) animated skeleton blowjob blue blush blue tongue blush bottom sans digital media (artwork) duo ectotongue fellatio genitals grabbing penis licking licking penis male male/male male focus male only monster oral orange penis penis penis grab pixiv id 42770757 sans sans (undertale) sex simple background skeleton solo focus submissive submissive male sweat third-party source tongue uke sans undead undertale undertale (series) unseen male unseen male face upper body video games yaoi