Keep in mind it's only YOUR business if you are planning to go down that road with the person. Asking a stranger what's in their pants or how they have sex isn't something that's done. However, when you're going to have sex with a person this is when the questions become important. For some people whether they are cisgender (their assigned sex at birth matches their gender identity) or transgender (their assigned sex at birth doesn't match their gender identity) questions about sex can be uncomfortable, so always proceed with care >>> which includes how you ask the questions.
Here's a video by Davy Wavy
Mr. Google is a great place to find basic information to help you form your questions. I wrote a blog post about the hot button topic of surgeries someone who is transgender may or may not have/want. Again, information is key. It was my hope to assist you in building a foundation to put the knowledge you learn from various sources into a framework.
I think sex is a subject people should be more comfortable with in the abstract then maybe when it comes down to specifics about the activity itself with the partner(s) of your choice it might be easier.
Illusions & Dreams is about two sets of best friends who are very different. Two of the characters are transgender and are on opposite ends of the spectrum on almost everything. They desire extremely different things in terms of what they were looking for in a partner, how they expressed themselves, what they wanted sexually and what they thought of affirmation surgery.
If you know me you know I don't shy away from sex and think fade to black is cheating. So there are several scenes depicting a variety of sexual activities: masturbation to sweet sex to kinky sex... because everyone is individual.
I hope the biggest take away from this post is: Everyone has different needs and desires and use care finding out how to best satisfy your partner.
Major Hugs, Z.