Of letting him Ciuman her .I think because she was stripped so bare , when Sawyer says "I was trying to give anda hope ". the idea that in all his hell broke he was trying to protect Kate broke her down .It opened her up to offer him this little nugget of Cinta , which was her kiss. Even after she did it , she still was afraid to admit why she did it. He asks "what was that for?" she says "I don't know" when clearly she knows . Obviously , the actual answer is "I Cinta anda , and I don't know ho to say it , because I'm afraid to say it" .He's so much like her, when she says that , he hears it 'I Cinta you' and then he kisses her back . I think writers did it so beautifully because it was real and grown up !