“A deal’s a deal” [MF]

Throwaway account for obvious reasons.

This story takes place pre-covid, I was 18 at the time, in a relationship, enjoying life. My bf and I decided to go on a vacation with my sister and her husband along with her brother and his friend. Confusing, I know, 6 people in total, 2 couples. Me, my bf, my sister, her husband, BIL, BIL’s friend.

As for my build, I’m an average woman, 5’4″, ample boobs and ass, decently fit. As for the man in this story that matters, my brother in law, he’s about 6′, also decently fit for someone who doesn’t really try, at the time he was 24. Not sure if more details are needed but that should give you a good enough picture.

Now onto the story, we all decided to go cancun one winter. This is a much different climate from what we’re used to in the northeastern US, so to escape the cold we decided to go to the always tropical cancun. We arrived, checked into our hotel, each pair had their own room with our room connected to BIL and his friend. Convenient, I know. Our first night in was tame however things got interesting on the second day.