Another idea is that they are on a beach. The waves are crashing gently on the shore. Nick and Grace are walking hand in hand, sharing stories and laughter. Then, they stop and face each other. Nick brushes a strand of hair from Grace's face and kisses her, with the ocean as their witness.
Perhaps they are at a town festival. There's music and dancing all around. Nick and Grace get separated in the crowd for a moment, but then Nick finds her. Overwhelmed with joy at seeing her again, he pulls her close and kisses her right there in the middle of the celebration. It's a spontaneous and exciting kiss.
One scenario could be that Nick and Grace are in a beautiful garden. The flowers are in full bloom and the sun is setting. Nick gently takes Grace's hand, looks into her eyes deeply, and then leans in for a soft, passionate kiss. The butterflies flutter around them as if celebrating their moment.