Well, ya, it was sex abuse. But imagine what she was exposed to, to do that with U! Kids do NOT naturally go that far in sex play. Its more like "Show & Tell", not "DO".
Sex abuse is Unwanted sexual contact, regardless of the age of the Perp and Victim.
Its always abuse when minors R involved, ALWAYS. Children can Never be consentual participants. Even if it felt good, or U liked it, or you went back 4 more. There is a coersion there. Perhaps unspoken. But children dont have the hindsight or foresight or understanding of how things are SUPPOSE to be. U R manipulated, brainwashed, or perhaps afraid, or loved the Perp. Its still coersion, whatever the method. But an 8 yr oldis in the same boat as you, F--- Up messages about sex, "private parts", and the such. You were both victims of someone else. May they Rot In H--L!