I think there is a very high probability that they know even if they haven’t said anything to you. Unless you’re able to hide it 24/7—and you would have to be a fantastic actor to be able to do so—there is just no way that some form of your slutty sissy alter ego hasn’t shown. They look at certain thing, you know? They way you talk, they way you express yourself, how many male friends you have, how you act around those guys… just to mention a few.
I mean, it’s really not that hard to notice, most of the time. Some girls might be more forward than others, but at the end of the day, if you guys are friends, they will talk about you, and they will wonder, at the very least, if you just so happen to like cock. Maybe they won’t be able to tell that you like to dress up, or that you want to be a girl like them—that takes a bit more insight than your average girl possesses—but, that maybe you are, quote unquote, gay? Yep.
Now, the bigger questions are: do you think they know? Do you want them to know?