There are gonna be sex scenes in the future for sure. As for the latter question... I don't want to spoil that much, but yes the story will continue even after officially becoming a couple. As for where it will lead, we'll see~
I understand the spoiler part, I do like surprises though I will say this one thing, it's always best to collaborate with someone cause it can be either beautiful or terrible, it depends, DyneWulf. did this and it improved, not saying your way is bad or anything...just giving you pointers
