Xbooru - 2010s 2019 2boys animated skeleton artist name artist signature blue blush blush bottom sans crying duo fellatio fire elemental grabbing head grillby grillby (undertale) grillsans hand on another's head hand on head head grab male male/male male focus male only monster monster boy penis penis in mouth sans sans (undertale) seme grillby sex skeleton skerbbie solo focus tears top grillby trembling uke sans undead undertale undertale (series) unseen male face white background yaoi