In the confines of a cramped closet, a curious sister can't resist her brother's throbbing erection. She tentatively reaches out, her small hand wrapping around his thick shaft. He tenses, but she's already stroking, her grip firm and eager. She leans in, her tongue flicking out to taste the pre-cum beading at the tip. He groans, his hips bucking forward as she takes him into her mouth, her head bobbing up and down, her lips stretched wide around his girth. She sucks hungrily, her hand working in tandem with her mouth, until he explodes, his hot cum filling her mouth, spilling down her chin.