If you don't though, perhaps better not to try.
I assume that most men in trans porn spit right after the camera moves away.
If you care about her, it wont bother you.
.
If you are in a relationship with a non-hormonal trans girl and this is right for both of you, just know that you have to 'commit' to it.
Looking up and seeing that sexy womanly form all perfumed up to the 'Nines' is superb but you cant chicken out once that mouthful of salty musky goo comes out.