Requesting Silk shocked by Monster-Saya's huge cock hardening.
Reference includes: Silk on the two bottom left images. Saya in her fused-with-demon monster form on the other four bottom images.
Top images are an idea of what would be happening, doesn't have to be 1:1, it's just what I imagine would be the easiest angle to draw. Maybe Silk is trying to calm down her big bad villain and gets surprised by Saya sporting a huge futa cock in her monster form.