Best Left Unspoken Part One

My sister, Lily, and I go away together on vacation. I booked two rooms, but it turns out the hotel is overbooked so we have to share a suite. I assure Lily it'll be like old times when we shared a room together. When I decide to take a shower, Lily gets comfy in bed, wearing only a tank top and panties. When I comes out, Lily decides to turn in for the night. When Lily falls asleep asleep, I reach over and start to touch Lily. At first, she wakes up and tells me to stay on my side of the bed. But, a little while later, I can't help but try to make another pass at her, reaching up her shirt and groping her tits. Surprisingly, she reaches under the covers and starts stroking my cock lightly.