So a long time ago I was watching this "adult" movie, french iirc, vaguely remember, will take some creatively liberty and put it in my own words -
Two brothers having dinner at a restaurant, it's the younger brother's birthday. An adult movie star arrives at a table next to them, the younger says to older, sh'e my favorite, I wish she would give me a BJ. The older says lets go ask, so they walk up to her table, and older goes - This is my bro, it's his b'day, can he get a BJ? To which the star says sure, unzips him and start BJing. In a few minutes he's ready to come, and says, I am about to come, so she removes her mouth and starts tug job, at which, the younger asks, can I come in your mouth please? She says no, you are too young.
They wrap up, she cleans with a napkin, happy ending, but the younger, a bit frustrated, asks the star that everyone keeps saying that I am too young, when will I be old enough to come in mouth? And she says, "When you stop asking".
Moral, just do it, stop asking, makes you a baby.