Chiaki gulped for air as Kana slid a probing finger into her vagina. It was greeted by the moist insides and penetrated with it's entire length. Kana pulled it out only to push it back in with greater force. Chiaki's gasps were perfectly timed.
"You're awfully quiet, sis. If you want me to stop, just say so."
"Kana, s..." Chiaki's sentence ended in a squeak as Kana drove another finger into her.
"If you want more, just moan, 'kay?"
Kana let go of her sister's legs and slid into a more comfortable position, leaning over Chiaki. She began licking her sister's pulsating chest, ribs and navel.
Chiaki was in a hopeless situation. The grip on her arms was loosening but she was not capable of escaping. All her efforts to think were in vain as Kana's two intruding fingers dug deeper than anything before. She struggled against the warmth but was hit by her sister's erotic steamroller.
Kana saw Chiaki being somewhere else and let go of the limp arms. She turned around and let her tongue dance over her sister's excited clitoris. Kana's buttocks were halfheartedly slapped, and the last bit of resistance caved in. Chiaki drifted away on a sparkling pink cloud of joy.
As Chiaki regained consciousness she opened her eyes to an extreme closeup of Kana's face. She felt their breasts touch and their lips were engaging in a gentle kiss. As Kana saw Chiaki wake up, she pulled away. A thin string of saliva connected them.
"You're amazing." Chiaki slurred. As she realized what she had said, she