Didn't you just get done doing precisely that?

[Is it a low-hanging fruit? Absolutely. Was she going to miss the chance to tease him? Certainly not. With a soft chuckle and a hum of anticipation, she straightened her back a bit to let him get at her clasps easier.

A shiver goes down her spine as he unveils her back, anticipation running through her. His fingers go... straight for what feels like one of her scars. Oh, Kiritsugu. Always thinking of what causes him the most pain.

She giggles when he kisses her shoulder, and reaches back to stroke his cheek.]

I'm certainly glad you think so. This would be quite awkward otherwise.