Since mine is so recent and I wasn't single when I had it done, I have no experience with leading into it, but when I was uncut my second gf freaked when I attempted to lead into saying that I had foreskin. If I remember correctly, I led into talking about surgery and steered it to saying that "Luckily I haven't had any surgeries done on me, especially after birth". She was like "Sure you have, every baby had THAT done". I was like "Not me". Then she quickly realized what I was talking about, and she like "no way, you're uncut!?". She never saw uncut before and at least to me she was more freaked out that I had extra skin than just being surprised. She didn't mind it, she thought it was in her words "weirdly cool". That was the only instance of me trying to sway a conversation into that direction. The other two gf's I just let them discover it for themselves. One had a surprised reaction, the other one didn't really notice until she moved it xD.