"best friends"? 😒🤔

So let's just name them Jessica and Amanda for this... Jessica and I have been friends since 8th grade year and were now seniors in high school were best friends and we've spent so much time together. But back in October her and her boyfriend broke up obviously I was there for her support and so was Amanda. I've known Amanda since 6th grade. We weren't like friends but more like acquaintances through middle school and a little bit through high school until all three of us started hangout summer of Sophomore year. We're a trio of friends. But lately I've been feeling like they're hiding stuff from me. Like Jessica and Amanda favor each other more, like they tell each other more things that they won't tell me. And I know it doesn't matter but Jessica and her boyfriend were together for a year, she'd always go to his house to hangout like all the time. I've asked if her and him had sex or if they've done anything, she's always said no and of course I took her word for it. But one time in math class Amanda was asking me if I was still a virgin and was like yeah and asked why and she said she was just wondering. Then she said "two of my closest friends aren't virgins" so automatically I thought Jessica and some other girl that she's known for some time, I guessed and said their names and she said "even if you guessed them right, I wouldn't tell you." And I was like "alright." And was like whatever about it and moved on. But recently I've noticed that Jessica's ex blocked me on Facebook and I thought that was weird like what did I do. And I asked Jessica if she was still friends with him on Facebook still, I was just wondering cause I know some people are still friends with their ex's which is fine cause that's their business. But she's tell me no that their not, my boyfriend looked him up on Facebook and looked at mutual friends and she was still friends with him. Like? Why would Jessica lie to me about that? And it got me thinking what are Jessica and Amanda hiding from me? Like if anything and from the looks of things, Jessica and her boyfriend had sex. Even though she's my best friend and I'd ask and she'd tell me no but from the things I've been noticing they obviously did stuff, and I just think whatever it's people's sex life. And yeah obviously I feel somewhat butthurt about it cause why would she tell Amanda that but not me? But it got me thinking since there're being weird about it and hiding it… what else would they hide from me? 😞