You've always had a thing for your wife's Sister... but lately your secret urge to fuck her has got out of hand. She arrives to your house, wanting a chat with your wife, but your wife is busy talking to the neighbour outside... so she is left on her own with you. She is an introvert, and her husband doesn't give it to her as often as he should... she's desperate for sexual attention.. she just doesn't know it yet ;)