I lived in Colorado when this occurred, many years ago. I went to college in North Carolina, and that is where I met my wife and lived for many years before we decided a change of scenery was in order and moved out west. My family was originally from Texas, but my wife's family was all from the North Carolina region. Her parents had passed away, but her sister still lived in the North Carolina area along with her husband and 3 kids.
My work was still headquartered in North Carolina, I had just been given the opportunity to work remote which is what allowed us to make our move out west. Still, I always felt it important to get some face time in at the office, which meant I flew back about once a month to spend a few days there.
Although I would always spend my time at a hotel, I'd make sure I had the opportunity to see my sister-in-law and her kids to keep up relations. I loved her kids and would do anything for them. I'd watched them grow from toddlers, eventually blossoming into the young women and man they became.
Tonight was a special night. Stacey, the youngest of the two girls, had just turned 18 and as I had done for her older sister, I was taking her out to a nice dinner, just her and me, to celebrate her birthday. I picked her up, my breath catching a little as she opened the door. She was dressed to the nines, and she was the ultimate combination of innocence trapped inside a blossoming body, with just a hint of baby fat both in her face and her breasts. I know I shouldn't see her that way, but I am a red-blooded male and she's related by marriage, not by DNA!
She came running up to me and threw her arms around me. "Oh my god Uncle Mike, it's so good to see you! I'm so excited about tonight!"
Releasing me, she turned around and shut off the lights, locking the door behind her.
"Where are your parents? I'd like to say hi." I asked.
"They went up to their campsite for the weekend. They figured I'd want to celebrate with my friends, so they left me home!" she replied.
With that, I escorted her to my rental car and opened the front door for her. Climbing in, we headed off for a local upscale Sushi place. We had a pleasant dinner, where I got to ask her about school, where she wanted to go in life, her friends, and social activities. She was happy and bubbly the entire time, and although she was my favorite niece, I learned more about her this trip then I had in all my previous visits.
After dinner she asked if we could use the pool at the hotel. It was hot and muggy, and they didn't have one so this would be an opportunity for her to cool off. I couldn't think of a good reason not to, so I offered to swing by her house so she could change into her swimsuit.
Stacey blushed a little as she confessed that she had her swimsuit in her purse, as she had planned on asking me all along. I felt a little uncomfortable that she would be changing in my room, but I had enjoyed the evening so far and didn't want to disappoint her so I took the next right and headed to the hotel.
When we arrived, we headed to my room on the 3rd floor. It was a basic hotel room, king bed, mini-fridge and microwave, and a bathroom off the entry hall.
"Help yourself to the bathroom to change." I offered. "I'll find my bathing suit and change when you're done."
Stacey smiled and headed into the bathroom carrying her purse. While she was changing, I pulled a nip of vodka I had in the freezer and poured it into a bottle of Pepsi from the fridge, and took a stiff drink before opening my suitcase and digging around for my bathing suit.
As I pulled it out, I heard the bathroom door open. I turned around to find Stacey standing there in the skimpiest bikini I had ever seen. Her young skin was so smooth, and her breasts were deliciously exposed at the top, providing a view into the ample valley between them. I felt my cock stir but I scolded myself for seeing her that way.
"Just give me a sec to change and we'll head down!" I told her with a grin, as I grabbed my suit and headed into the bathroom. I closed the door behind me and locked it, then put my hands on the counter and leaned forward, staring at my reflection in the mirror.
"Bad, bad, bad!" I thought to myself as I tried to shake impure thoughts from my head. I turned the cold water on and splashed a little on my face to try to shake me free of my thoughts. As I turned to grab a towel, I realized that Stacey had left her bra and panties in a ball on the end of the counter.
I stared for a moment, convincing myself not to do what I already knew I was going to do. I reached over and picked up her panties, then pressed them to my nose and deeply inhaled, savoring the scent of her young womanhood flowing into my nostrils. My brain was short-circuiting, and I felt faint.
Realizing that she was waiting, I snapped myself back into reality. I placed her panties back in the ball with her bra, stripped down, and put my bathing suit on. I hoped that my lust wasn't too obvious from the bulge in my suit. I turned and opened the door, noting her dress hanging neatly from the hook.
As I walked back into the room, Stacey whistled.
"Not bad for an old guy!" she teased. "But are you sure you aren't having prostate issues? You took a while!" she giggled.
"Smart ass!" I replied, dropping my clothes on my suitcase. "Let's head down to the pool before this old man needs his nap!"
We headed down to the pool area. Stacey skipped ahead of me, while I took the opportunity to enjoy her tight young ass wiggle, barely contained in her bikini bottom.
"Bad, bad, bad!" I continued to think to myself.
When we arrived, I opened the door with my key card to find a mostly empty pool area. There was an older couple sitting in the hot tub. Stacey ran right over and jumped in the deep end, surfacing with a splash and a shriek as the cold hit her. I took the cowards way in and dipped my toes, before relegating myself to jumping in; like ripping off a band-aid.
As I surfaced, Stacey splashed me then swam away giggling. I turned and swam slowly towards the shallow end, then sat on the steps with just my head above the water and watched her swim around lazily. At least the cold water was causing shrinkage, so I wouldn't be embarrassed when it came time to get out of the pool.