I think it all boils down to respect and formalities. Like for me personally I'm a very crass, blunt, offensive person. All of my friends and I are that way (cis and trans). In fact and my trans guy friend always throw around trans since at the end of the day we know that we love and respect eachother as really good friends. But would we go about tossing that word to others? Of course not. It's obviously slang that can easily be misinterpreted as derogatory.
The way I make it easy is whenever partners/hookups ask how to adress my genitals I just tell them to just simply address them.
A penis is a penis, a clitoris is a clitoris, no matter who it's on.
Genitals aren't exclusive to gender identity, and it's just harder to lump them together: manclit, lady dick. It's just awkward and cumbersome if you ask me.
I am me, I have a penis, though I am not my penis.
At the end of the day I throw the word around in the bedroom because I know my partner is putting his best foot forward and trying to make me happy by tryong not to offend me, and I appreciate it, so personally I diffuse the seriousness and keep the energy flirty and playful.
Just be respectful and open the conversation. If the person is unwilling to be patient with you and educate you on where their boundaries lie, you really shouldn't be involved with them to begin with. Communication is mutual and you cannot be expected to respect boundaries that are unestablished.
