I read a futanari manga (genetic girls with penises) and was very turned on by the concept of a woman with a penis. I discovered that the penis is not feminine or masculine, but simply an appendage. So I started getting into shemale porn. And for as unrealistic as it is... it sure is good fappin...
Unfortunately I have not met, dated, or seduced a transgendered lady so far, but I'm working on it, hehe