Natasha kisses Daniel to make him stop talking. She thinks that if he keeps talking, she'll love him, and she can't afford to do that. Kissing, however, is just another way of talking, so kissing him maybe wasn't the best idea. Daniel thinks that someday, he'll write an epic ode to kissing called "Ode to a Kiss."
The fact that Daniel's words are what's turning Natasha to his way of thinking suggests again that she's not actually against passion; rather, she's consciously and purposefully ignored passion to protect herself from harm.