You yourself said that you take energy from others correct? Thus, if the individual is having their energy drained with no benefit to them would that not then be parasitic relationship? Ergo, you would be an energy leech. I feel individuals use the term "vampire" to romanticize what is actually occurring, when in fact they are not a vampire.
Also, you have contradicted yourself by saying that you are a "psi vampire," but that you don't need the energy. According to the posts I've read pertaining to individuals that believe themselves to be such or by those that have studied such individuals (I remember reading a post my chiron on here somewhere that explained this topic), they actually have a need for said energy.
Either way, your taking energy from someone whether you need it or not. If the individual is receiving nothing in return then you are acting in a parasitic manner.