For those asking how: Sometimes boners fade, especially if you're stressed or your partner does something that you're not into. Switch it up and it usually comes back.
Its also very common that the first time kinda sucks. You're learning a new kind of dance and there's all kinds of pressure to perform.
I'm gonna stop reading here. I'm bored of the conceit and there isn't enough emotion to keep me invested.
I started cause I heard the smut was good but eh. Non-con of the kind in the first arc and incest ain't my cup of tea.