Just go to bed.

You softly shake your head at your sister. You're just too tired from all of the emotional turmoil of the day. The two of you agree to speak bright and early in the morning, and you traipse up to the bathroom to shower and brush your teeth while Gwen bustles around downstairs tidying things up a bit.

You get back to your room and strip off the tight-fitting loaned outfit from your sister. Naked once again you look at yourself in the mirror, lit only by the moon, and are once again surprised at just how hot your new body is. If you were still a boy, you'd be hopelessly in lust with this girl: her slim frame, wide hips and luscious ass, hefty tits and beautiful face would drive you wild. You allow yourself a look at your crotch and marvel at the plump, hairless pussy lips nestled between your skinny legs. You plant one foot on the bed to get a better view and gently explore your glistening cunt, this time able to see your fingers slipping into your hot, dark opening.

While the sensation causes you to shudder and bite your lip, you find yourself still in control, obviously still sated from before. You stand there for a moment more, frozen with two fingers in your pussy and your legs spread, trying to decide what to do next.