Kinder? No way! Then you'd never have any fun at all! What kind of life is that?

[That sounds horrible to her, without reading his thoughts.]

And besides... a little step on the foot isn't going to seriously hurt me! I'm tough!

[She gives him a grin. She's not as tough as him, of course, but she's tough enough is what she means, not to have her entire life ruined by her foot getting stepped on or getting bumped into or similar in just one dance with him.]