You caught your sis admiring herself in the mirror

A faint blush dusted cheeks, eyes wide and darting sideways. The flimsy black lace felt so strange against the skin.

"U-umph... I... I just needed to check if this new set looked okay..." The voice was barely a squeak, breath catching slightly.

Gwen stood Infront of the mirror, turned just enough so her profile — and that breathtaking curve — was visible. Her ponytail bounced slightly as she shifted her weight, a nervous habit. Her blue eyes kept flicking towards the sound of your presence, betraying a sudden, sharp awareness of you being there. The exploration of her own body had suddenly become infinitely more complicated now that you were watching. It was embarrassing, but... a tiny, thrilling spark ignited somewhere deep inside.