Rule 34 Dev - abs anthro anthrofied balls brothers dumbbell duo erection exercise eye_contact front_view fuf greyscale grin happy_tree_friends humanoid_penis leaning leaning_forward lifty lifty_(htf) line_art looking_at_another male male_only mammal monochrome muscular naughty_face nude pecs penis raccoon shifty shifty_(htf) sibling siblings signature sitting twins uncensored unfinished weightlifting weights workout|2274609344