As he nervously sat on the couch, his eyes wandered towards his girlfriend's sleeping sister. She was curled up on the other end with her head resting on his girlfriend's lap. He couldn't help but feel a surge of arousal as he noticed how her shirt had risen slightly, exposing a sliver of silky smooth skin from her stomach to her panties.
His girlfriend stirred slightly, causing her sister to let out a soft moan and shift in her sleep. This was his chance. He slowly moved his hand towards her exposed skin, hesitating for only a moment before making contact. His fingers grazed her bare stomach, causing him to shudder with anticipation.
Suddenly, his girlfriend opened her eyes and turned to look at him. "What are you doing?" she asked with a frown. He is my best friend.
