When I was growing up I thought that getting a girl's phone number was a great step in the whole dating process because that is how society conditions us to think.
Step 1: Get a girl's phone number
Step 2: Ask her on several dates
Step 3: Sex
But when I lost my virginity this is what happened
Step 1: Sex
Step 2: Girl puts her number in my phone without asking me
Step 3: Girl ends up flaking
This is reality, sex always happens before the Number Close given the logistics work in your favour. If logistics work against you and a woman feels an emotional connection with you and fears that she may not see you again, she will be the one to suggest a number exchange. It should never be the goal of any man to get a woman's phone number, it's just something that happens, an ofshoot of attraction.