I am glad to hear you were the same age when this happened. I don't think there's any issue of abuse in this case if you were both willing participants and neither was appreciably older than the other.
What Raze said about it becoming an issue within the family may still be right. If you shared this with them, there may be repercussions whether they are deserved or not. Keep that in mind because there are few secrets that are never found out.
I think many of us feel a special bond and freedom with our first sexual partner. They helped us explore something that was completely new when we were at our most vulnerable. If that first partner treated us with respect and kindness, they are easy to come back to. However, for the purpose of personal growth, coming back to a sexual partner you aren't in love with may not be wise. If you want to move forward and find someone to share your life with in a loving relationship, this habit may hold you back. Think it over...