This is amazing! And there's still more to come! I love the view from behind - there's something about the tf-ee not being able to see what's happened to him from the angle we do. The pants which are stretched across the hips, the ass has grown round and large. The realisation of his fate. This is TF heaven.
You've also done a great job with the clothes - having them like that really sells the idea that they fitted and his body is changing within them. The pants have fallen, getting caught on the hips. The top off the shoulder. Honestly, this sequence is wonderful.
Looks like she still has a penis in this frame? I hope so, I really wanted to see that transformation in detail. Her manhood getting smaller and smaller until *pop!* it's gone.