rule 34 after anal ambiguous gender anonymous artist anthro anus armless arrow anatomy ass big butt blue clothing blue shirt blue topwear blush bodily fluids clothing darkner deltarune duo female gaping gaping anus genital fluids genitals gesture human looking pleasured lying mammal monster on front open mouth pink body pussy saliva shaking shirt short stack simple background speech bubble spiral eyes sweat tears teeth text thumbs up topwear trembling undertale series virovirokun 7629164