It is possible to finish with her inside her or out side her if you will follow the below guidlines:-
1. When you meet your girl friend don' t start intimate with her immedaitly.
2. Frist start orally giving and receving.
3. Never use any medicine like vigira.
4. Ask her to play with your penis with hands, mouth and tounge.
5. Drink a luke warm glass of milk before having sex.
6. Try the different sex position during the sex.
7. When you have sex don't make any haste do slowely and constrate your mind on sex and vigina of your girl friend.
8. Feel what is happening inside her vinina with you penis and move slowely in and out in hre vigina, feel the heat of her vigina and breath.
You will really finish in her.