"Be good!" was the last thing I heard as the front door shut, signalling the beginning of my week of freedom. My name is Jay, I'm a 25 year old dude freshly finished a finance degree but honestly after feeling burnt out from the grind of exams I wasn't in a rush to get out into the job market. My sister Kim is 19 and just starting out next semester, her and my parents have just left with all her stuff on a week long trip to help move her into her dorm.
I'm a pretty well built guy, I like to take care of my body, so you might be wondering why I wasn't asked to help with the heavy lifting but therein lies the twist. The power to swap bodies has run in my family line for generations, we've been good about keeping it a secret from outsiders so nobody but direct family has found out so far.
"Safe travels, is Kim not going with?" "Thanks Mike, no we're going to move her stuff and she's going to follow along later" I hear my dad explaining, slightly exasperatedly to our neighbour through the door. Mike is a balding middle aged bachelor who has lived next door since I was a kid, he's a bit creepy and I've caught him eyeing up mom and Kim a few times but he seems mostly harmless. He basically lives in a dirty white tanktop and sweats and his house is a bit of a mess but surprisingly he's a very good handy-man and does a lot of work on our house for free(probably to ogle at the women).
Walking from the front door I stop at the full length hall mirror and take in Kim's body. Kim didn't give too many ground rules for the week, she mostly wants me to keep up with her gym schedule and do some tanning so she's bronzed for the first week of college. Even though she's my sister I have to admit, Kim is gorgeous. She has long blonde hair, blue eyes, big lips, tiny waist, a little short around 5"2 but looks like a model. She keeps herself in great shape which makes her perfect C-cup breasts stand out even more and a fantastic ass built by squats. One of the side effects of being in someone else's body I've noticed is the longer you're in there the more of their psyche bleeds into yours, as I hear the car pull away my focus is drifting from her sexy features to noticing her slightly pale skin, which means it's time to go lounge in the sun by the pool.
Stopping into her ground floor room to look for something appropriate was a challenge, she keeps it like a pig-stye. After a few minutes of digging all I could find was a couple of one-pieces which would be no good for tanning and a bikini that looks like it was more string than fabric. After stripping off I took a minute to get a feel for my temporary body, running my hands along my neck and chest. As my fingers ran across my new breasts and reached my nipple I felt a little flutter, I don't remember Kim being so sensitive last time I was in her body but that was a couple of years and some development ago. I kept one hand caressing my breasts as the other ran gently down between my legs. It's takes some time to get used to the emptiness down there but as my finger traced the outside of my folds my breathing was getting a bit heavier. I explored with one finger until I brushed against my new clit which caused my breath to hitch. As I was getting wetter I brought my other hand from my breast down to start fingering myself as I rubbed my clit. Women's pleasure was such a different ballgame to men's, I could feel the orgasm slowly beginning to swell as little moans escaped my lips. My eyes closed, lost in the mounting pleasure, unaware of the world around me as my breathing got faster...*thud*, a loud sound snapped me out of my stupor.
I got up and peeked out the window and couldn't see anything unusual but a bit of wetness on the ground, a bird probably flew into the window and hurt itself. I was riled up and a bit frustrated to be interrupted but I'd lost my rhythm. "God damn it" I thought. "I'd better make the most of the daylight hours". The last time I had a chance to do something like this the orgasm was much stronger after all the build up so at least I had that to look forward to later.
I finished attempting to tie the bikini ties, grabbed some lotion and headphones and got settled in outside. The day was a scorcher so I had to make sure I was thorough with the lotion, cursing that I didn't think to put some on before the bikini I managed to work my fingers around it without messing with the ties too much. Doing my back was the worst despite Kim being much more flexible than me. After a little more light teasing of my body I settled in, closed my eyes and listened to a podcast while the sun did it's work.