"Oh come on, Nina...You really have to stop apologising to me for everything, or else anyone who might see us would think that you're the little sister that always messes up while I'm the older brother who cleans up your mess."
I joked around, which made her let out a chuckle and roll her eyes, like there's no way anyone would consider such a young boy to be her older brother.
I then said, while eyeing up her waist and rubbing her hand in an enticing manner,
"...I also got to find out just how big the curve between your lithe waist and those wide hips of yours is because of your misunderstanding, so instead of you apologising, I should be the one thanking you for giving me an opportunity to lay my hands on that sexy body of yours."