Grandpa's cock twitches as the teen's small hand grips it tightly, her inexperience evident in her hesitant strokes. She looks up at him, her eyes wide with wonder and a hint of fear, but her curiosity drives her on. She leans in, her tiny tits pressing against his thigh, and takes the head of his cock into her mouth, her tongue flickering out to taste the pre-cum beading at the tip. She gags slightly, her throat unused to the sensation, but she's determined to please him, to learn the secrets of this taboo dance.