KassX, my current chapters tend to range around 10k, and I average 1-2 scenes per. Having said that though, I think it also greatly depends on how many characters you’re working with and the circumstances that are going on. A lot of times my main character, Alex will feature in both scenes. But sometimes he’s only in one. There was also a point in the story where he was gone for like 5-6 chapters and none of the sex scenes featured him. To me, the plot should ALWAYS dictate the smut. But, having said that, I AM writing smut so I always try to include at least one scene in every chapter. I also think that its more important for the smut to make sense and further the plot than to just be something gratuitous and tacted on because you needed smut.
I don’t know if that helped, lol I just wanted to chime in!