My son is gay. Recently I asked him, would you consider having sex with a trans man. He pondered it. Then he said, “I think so — it’d be interesting to have a different kind of sex while still being with a man.” (this was an unprompted, uncoached answer.)

You're a transwoman asking your son if he sees transmen as real mean. The very act of asking is prompting a particular answer. He knows the answer that you want to hear and knows that it will remain entirely hypothetical for him. And I'm sure you've taught him plenty about how to navigate a minefield of narcissism when presented with an obviously leading question.

What I define as bigotry/prejudice as pre-conceived notions of who one would sleep with or date, driven by cultural constructs or assumptions, without personal experience.

"How can you know you don't like dick if you've never tried it?"

By this I am not accusing lesbians who don’t sleep with trans women of being bigots, every last one of them. I am inviting each person to explore themselves, in their heart, and see if they find pockets of prejudice.

No, it's not an invitation. I know this because I've seen what happens to lesbians who decline it.

I once had a white lesbian tell me, “I could never go down on a Black woman.”

No, you didn't. You're a liar and you're making this up. Also, you're a disgusting racist.

What I’m trying to have you consider is that there is a lot to unpack here,

I've found that whenever someone says "there is a lot to unpack here," it's best to just throw away the entire suitcase.

and I’m just hoping to start people thinking about all of this.

No, you're hoping you can coerce lesbians into fucking you using the specter of bigotry. You're a rapist.