A lot happens at once. First, Nida's eyes go wide because, holy fuck that was a thing that was just said. And with that bluntness that Nida had experienced a few times back home when he was being particularly dense about someone hitting on him. Second, he failed to stop walking backwards.

Third?

He tripped over a rock. Inelegant, embarrassing, and potentially painful. Except, of course, what good trained warrior didn't have some muscle memory to work with. The fall turned into a quick cartwheel was it sad he'd tripped enough that he had to develop muscle-memory catches for when he had a polearm on his back and came to his feet again staring at Bull.

Note to self: stop tripping in front of people. Geez.

"Okay, just to make sure there isn't any cultural miscommunication here, because I've run into a few with the other person from Thedas I've met, did you just suggest sex? And if so know that yeah, I'd take you up on that. Just because a guy should never turn down a possible once in a lifetime experience like having a Qunari keep him warm and well exercised."