No, the mc will not be the only character with sex scenes. I plan on adding brothels in towns the crew visits along the way that will open up choices as optional content. I honestly don't have anything set in stone as far as sex goes, but I do plan to try and add something for almost everybody as long as it's legal and doesn't violate terms. I know you want really specific answers, but I don't have them. I have the main story boarded out lightly through book 3 and a solid storybook completely done for book 1, but I change things all the time as I'm writing.