What the hell are you concerned about? The fact that you're an idiot? I'd be pretty concerned about that myself, if I were you.
The fact of the matter is that you're more "concerned" about the opinions of your tasteless friends than you are for your feelings for this girl. She very well could be a woman with a vaginal tweak. She very well could be post-op trans. Either way, she's a woman, and you need to bloody educate yourself not only on what it means to be attracted to someone, but what it means to think for yourself.
I mean, look at you. It's pathetic. You can't even just take someone for what they are, you have to "suspect" something and then come here seeking advice about something you're grossly uneducated about, hoping that we'll give you some answer that's going to enable you to... I don't know, "get to the bottom of this"? You already got to the bottom of it. You're attracted to her, you had sex with her. You like her, but honestly, you just sound like another selfish jerk who cares more about saving face with his homies than you do about actually having a meaningful relationship with a woman.
In closing, she's just a typical woman with fake tits, and you're just a typical man.
Get over yourself.
~ BB