<br/>Sarah suckled on the finger that had been offered .. almost disappointed when it was withdrawn from between her full wet lips . The look on her older sisters face ...the tone of her words ..and then .. she whimpered , Biting her lip . Rules were a dfficult thing for Sarah .. and the lust her sister seemed to be showing , the take charge attitude . It was unusual for Sarah to play a submissive but ... as Tony answered and then kissed her sister . Oh she wanted whatever , rules to it ...fine .<br/><br/>His hand touched her cheek and she turned and moved to suckle at his fingers .. opening her own legs to feel her sisters finger as it toyed about . A tremble cursed through her aching body .. as she kissed the tip of the finger . Nuzzling her face back into Tony's hand .. she knew Lacey wanted that answer .<br/><br/><strong>" Rules ..." </strong>she spoke softly .. leaning forward as she nuzzled her face against her sisters lap ... smiling up at her now. Amazed that this might really be coming to life ...tonight , right now ...<strong>" I not so good with rules ...but ...you are my sister ." </strong>giving a short pause ..<strong>" I do anything to please you ...."</strong>as she trembled , lifting more as she wanted her clothes off . Wanted Lacey's clothes off .. to lick and taste her .. watch as Tony's cock entered the only person she really admired and looked up to . Oh to watch her sister orgasm .. feel her body quiver , enjoy this final union .. become a true duo . Licking her own lips ....<strong>" What rules ...Lacey do you want . "</strong>her voice meek it seemed .<br/><br/>True this all started by the knowledge of how well endowed the man was ...wanting to know exactly what that felt like . Listening to the two of them earlier had fueled that on ...but more than anything , Sarah wanted her own sister . It was their relationship that mattered and needed to be kept in tack . She couldn't give up this closeness that had always been between them ...and now it seemed fragile in so many ways . Taboo , extremely naughty ...and yet she wanted it ..craved it . Maybe she wasn't the only one ... taking in the look on her sisters face .