I agree with Helioxis. Finding appropriate genitals and how they deform will take a while even those who’ve done this for a while don’t have that down pat. I do however disagree with JackRaptor. I think the expressions are a bit too extreme but for one if your first works I think they’re fine. You can prolly work on making them more natural if you wish. If this is your style however then keep at it.
I will try to better the material for the pussy, it could use some bumpmaps and wet effects. I will also try to make the expressiosn more subtle (they were a lot worse than this but I think I improved). About the vagina shape I think it will be a bit of a problem finding a natural vagina that deforms this much, but it was my first time going for this extreme so it might be possible to do better. Also the lighting is a bit too strong.