A few days in to a family vacation, my wife and her sister went out for the day and left me at our rental because I "had a meeting day for work"; but really what I did was take all of my SIL's used panties out of her laundry bag and smelled and licked them, or wrapped them around my cock while watching porn with girls that looked like her, for probably 7 hours. Her almost fresh discharge smelled sweet, and tasted better than my wife's pussy. One pair of panties even had a skidmark and I almost didn't use it but then I realized even her shit smelled good and used that pair to rub my dick with while watching an anal video that had a girl that looked so much like my SIL I could convince my brain I was assfucking her.

The first time I jerked it, I shot my load right into a pair of the panties, but that wasn't enough for me. I went back into her room and got her body lotion, unscrewed the top, and the next four or five times I jerked off I shot my cum into it. It was amazing the next few days watching her squirt lotion into her hands and seeing her unknowingly rubbing my cum all over her hands and tits.

In an unexpected twist, our return flight was delayed and the rental's laundry machine wasn't working, so we all had to re-wear clothes. I caught a glimpse of my sister-in-law changing and she was wearing the panties that I came inside. I took a shower and rubbed one out, thinking about my cum being so close to her pussy. If she noticed she didn't say anything, but she did swap seats for the flight home and was next to me, and fell asleep on my shoulder. I was looking down her top the whole time, admiring her cleavage. Now whenever she comes over to visit, she stays really close to me, "bumps" in to me, and has grazed my groin with her hand more than once.

I've been telling my wife how great the family vacation was and how I can do so much working remotely, we've planned two more trips this year. I almost can't wait to do it again and again.