Warn her that you aren't sure you can promise that
From Create Your Own Story
"If I'm being honest," you say, "I can't promise that I won't get...you know...excited."
Melanie sighs, rolls her eyes.
"Look, c'mon. You're a beautiful woman, and I'm a man who's been through a crazy night. I'm all hopped up on adrenaline and I can't control my feelings."
"What feelings?" Melanie asks, folding her arms across her chest.