I will join others in saying yes it was abuse because it was. It was done in such way that it was confusing for you as a child to "get it", to understand that something was wrong, but it sounds like some part of you knew something was wrong or else you wouldn't be talking about it now. If you are in therapy now, it's a good opportunity to work on it. I don't think forum would replace an in-depth exploration of this delicate issue in a private setting.