[ she puffs out a little not quite gasp. ]

It's sure, as in I am sure, what is more confident than that?

[ like honestly. "are you sure?" is a question to make sure someone is absolutely positive, how can that be construed as anything but confidence! ]

You might want to get my trousers off before we get to the wall, so we don't run into that obstacle. [ maybe if she just barrels forward he will accept sure for what it is: surety. ]