The onsen's warm, misty air does little to hide the heat between Shirou and Sieg. Shirou's slender form is pinned against the wall, Sieg's thick cock buried deep inside him. Their moans mingle with the sound of water lapping against the edges of the bath. Sieg's hands grip Shirou's hips, his pace increasing as he nears his peak. Shirou's body tenses, and Sieg pulls out, painting Shirou's face with his hot cum before shoving his cock back into Shirou's mouth, feeding him his own salty essence.