It's difficult to say what might happen at the cabin. In that excerpt, it does seem like all four of them will be going to the cabin at the same time (the four of them being Kayla, Jack, Amanda, and Allen). It's safe to assume that Kayla and Jack will have sex while they are there. After all, if I remember correctly, that was the original point for them going. At the same time, it will be interesting to see how it plays out with Amanda and Allen not being together, and Sam in the picture. A few questions I think should be considered are
Is Sam invited to go with them? Why or Why not?
Are the twins going at the same time? Why or why not?
What will happen between the twins if it is just the four of them? Let's be honest, a cabin in the forest is a bit of a romantic spot. Could something be rekindled with the twins at that point?
If it's NOT just the four of them, and Sam goes too, what could happen between the two of them?
I know it's a lot to think about, but there are infinite directions the story could go just from that moment alone. I'm excited to see what route Joe takes and how the story will play out.