Sex and V after NATURAL birth

I need some clearance here... Will sex still be the same after a natural birth? And will my V go back to normal? And is it true that a C section will leave you with a flabby tummy for life? I just want to know which one will be the best because I don't want to affect my sex life with my husband.. some people say your V after a natural birth will look the same on the outside  but inside it is like an OPEN PLAN house.. 😫😫
I have always wanted a C Section but you ladies gave me a whole different perspective about birth seeing all these natural beauties! 
I am almost 21 years old and I am a FTM 👊🏻
The docter told me when I was 6 weeks that normal delivery won't be possible because I am so small....but I will push my luck again!