The manga is Ryuu wa Tasogare no Yume o Miru by Akira Himekawa. It's about a boy who's a half human, half dragon experiment. There's only 3 translated chapters so far, but there's tf content in it already. I always love dragon stuff so it was pretty cool to me.
Process in chapter 1, page 18 (I think that was the page) and chapter 3 pages 26-30.
Mangareader link