Kandi grinned, stroking her sister's hair as she watched their daddy's cock disappear in and out of Kristi's eager pussy.  She licked her lips once; the sight turned her on so much.  She had always enjoyed watching Kristi get fucked by a dildo, or a strap-on, but this was the best, by far.<br/><br/>Her own excitement was probably nothing compared to her sister's.  "Fuck him, Kristi..." she said,  exhaling a moan of her own.