Friends.

1. a person known well to another and regarded with liking, affection, and loyalty; an intimate

I have had 3 best friends for 15 years: Danielle, Lori, and Wiss.

I know that I have made mistakes in the past that have hurt my friends feelings. I am not always the best person to be friends with, I make mistakes, even when I don't realize that I have.
I am sorry if I have ever hurt your feelings.
I will try my hardest to be a better friend, to be there for you more when times are bad, to celebrate more when times are good.
I want the next 15 years to be better than the first 15 years.
I love you like family.