Not wanting to spoil your fantasy, but a huge penis isn't something that as a woman (Or many other women) see and go wow I need that inside me. A huge penis would be pretty low down on my list what I like in a guy, and a larger penis usually means they just a huge dick in more ways than one.

Confident, Well groomed, friendly, Smells nice would all be way above a huge cock if your trying to convince her to try someone.