Also, let me explain another scenario that might shed some light.
Say someone is a transexual and I don't know and we go on a date.
If she takes it easy and shows she wants to take it slow all the while charming me and we get on so well I would really be attached to her.
If she comes out after a while and says " look shug, I'm a M to female/pre op", I don't know how I would feel. I would feel inclined to remind her how well we got on and how much I like her. I would need to think about it because I don't know how I feel about that. I'm into the feminine form but I don't like dicks so I'd have to deliberate and discuss that and I'd definitely strongly consider continuing with someone I liked so much. I'd ask for patience and thank her again for being so open. I'd feel bad that the world has to suck so much that I can't just immediately handle someone who is a woman as a woman. So basically it would be open.
If someone didn't tell me and I made out with them a lot and got publicly affectionate with them and then we get in the bed and suddenly I find a penis.. I would feel very differently.
I've spoken to a lot of friends about this and they all agree they'd feel compassionate if told in a decent time but suddenly finding a dick would send them into a blind rage and even make them start swinging. It would enrage me too but I like to think I wouldn't get violent.
It's just that if I don't know how I feel about that I don't want to get tangled in that too fast. I'd like to have time to accept the biggest test true test of my prejudices and tolerance. I don't want to suddenly hear friends saying "oh you're homosexual now" when I haven't had time to understand and have an open discussion. It's not cool if friends pull me to the side and say "why do you keep tongue kissing that person, it's a dude". I know that is so hurtful and wrong but some consideration needs to be given to the big change that a guy has to have and the feelings that we have to battle in the culture to make us actually able to handle it.
I know trans people say: Oh it's dangerous if we reveal it. The thing is as I revealed, I cannot see any logical reason to wait until someone who is potentially transphobic and homophobic and sees you as a "man" or a "freak" has kissed you deeply and fondled you thinking you are a woman (which you are) when he believes you're not. And also preferring letting them find out in a secluded bedroom over a public setting where people can help if they are crazy enough to get violet knowing before any sexual act.
If there is no sexual stuff then someone finds out, sure they might off but they will likely just fuck off. If they have gotten very passsionate with you, they may fly into a rage. Believe me the view point on this was unanimous. My friends are understanding of trans peeps but have (possibly misplaced) feelings of being "tricked" or "fooled into a homosexual act" if just not told until after.
The point in all this is the timing of revealing problematic facts drastically changes peoples feelings, so that it is often two extremes. It can make someone see you as amazing or selfish (yes unfairly so). So I hope this explains the difference. It really sets off a lot of guys. I know a friend who is the least violent and most calm and chill dude ever. If told after a while he wouldn't mind but if told after doing all kinds of stuff he said he can imagine an uncontrollable rage taking over him. So yeah please any trans people reading take that advice as you will.