He nods, a brief, sharp sort of thing. Grantaire's well aware Jyn likely needs something to unleash on, but he knew that when he invited her; he's not sure if it's healthy, but there's something calming, fulfilling about being left sore, within a safe context. And he's not planning to take it easy on her, despite all his joking about being out of shape.

They circle for just a moment before he advances, striking forward toward her shoulder in an easy "come on".

"To knockdown?" he asks, since they're not in the fray yet. "Best of three?"