Need some help coming out to this girl I like

It’s been awhile since I’ve been on here bc things have been going pretty well ig.

I haven’t had to really deal with being trans that much bc it’s been surprisingly easy to hide now that I pass. Until now.

A bit of context, there’s this girl (G) who I was mutual friends with I thought she was really pretty so I started hanging out with her and our other friends more often. We both have one main friend in common though, I’ll call her S. She’s on of my best friends we spend most of our time together. We both told S that we liked each other and she ended up telling us. So now we’ve gone out a few times but agreed to take it slow and keep it casual. No one here knows I’m ftm not a soul. G is however bi and has been with trans ppl before so part of me knows it’ll be fine but it’s still a very awkward convo to have. She also does mention that to be with someone she needs good sexual compatibility

So me and G are hanging out and decide to go to my dorm and chill. We end up getting super cuddly in my bed and she admits she wants to kiss me. In my head I got really flustered so nothing happened, which I regret now. I’m definitely a bit turned on but I know I can’t do anything until I tell her. I was walking her back to her place and she asked what I was thinking about. I said “secrets” which isn’t a great thing to say to a person. So she guesses a few times and I say no. Then she says “do you have a vagina” I don’t respond and just kinda look at her. Then she says she was just kidding and we move on. I want to tell her soon so that way I’ll know what she thinks and can move forward.

I haven’t had to do this in a very long time so I’m freakin out a little