First, may I call your attention to the guidelines for using the comments feature found here:
https://www.askmehelpdesk.com/feedba...ure-24951.html
You are using this site inappropriately.
Second, a 21 your old man is going to run from a 15 yr old girl if he is smart. He is an adult, you are still a child. This business about age being just a number is just your way of rationalizing. While it is true that the older one gets the less age matters, but when one is an adult and the other is a child it certainly does matter.
Third, this site does not allow chat speak. We type in full words and sentences here.
Finally, I have a lot of doubt that you are telling the truth here. I doubt if your parents have given you permission, I doubt if this guy agreed to go out with you. I think you are a 15 yr old fantasizing about a crush with an older man.