Idk if i’m going crazy and my bpd brain is messing with me but i’d like some thoughts and advice maybe?

so my boyfriend had been planning on going away to switzerland with his gbf and 5 others, i was last minute invited because my bf felt bad about leaving me at home after our own vacation was cancelled. 

it’s day 3 or 4 of our trip, we are all living together in this girl and her brother’s chalet. I’ve been picking up this weird energy between my bf and his female best friend the whole time, they have this weird husband &amp; wife dynamic.  She keeps constantly talking about how much my bf’s parents love her and stuff.  I went to the supermarket with them and i legit felt like i was their daughter. 

Then tonight, me and her had a bit of aperol and she got up and danced and shook her ass in my boyfriends face for a good 10 seconds. 

I’ve been in my room ever since literally hyperventilating. my bf says he didn’t like that she did that and assures that nothing has happened between them (they’ve been friends for 10+ years)  but my brain is making up all these scenarios about what could’ve happened if he hadn’t last minute invited me on this trip. 

im freaking out big time and i just wish i could calm down. i have never really been threatened by her as she’s always been so lovely to me but being on this trip with them both as just made me go crazy, they literally act like a couple cooking and watching movies and teasing each other.

I feel like i’m sabotaging maybe? idk!!!