Should I be angry with my boyfriend?

Laura says:
My best friend is close friends with my boyfriend and the other day she went to his house to study but they ended up just watching a movie, my favourite movie. It hurt my feelings because they never even told me that they were going to do that. They meet up alone sometimes and make plans with eachother, but I just feel jealous because I feel like that should be me. Just by the way she has a boyfriend but doesnt have a very good relationship with him. They talk and text all the time and Im usually fine with it but it just really bugged me this time. I feel silly bringing it up because she is my best friend and they didnt do anything. Its not that I dont want him to have any friends that are girls, I just dont think that its appropriate for them to do that without even telling me or my best friends boyfriend who doesnt even know about it. A while ago when I wasn't around they also went to the movies alone together.
What should I do? Do you think I'm being paranoid?
Thanks for the help :)

You're not imagining it - this isn't right. If he is keeping his meetings with her from you, they are spending time alone together and her own relationship is rocky, anyone would be suspicious. And you don't actually know if they did anything or not. I think expecting you to accept all this is too big an ask. Never trust a man who wants to be alone with another woman and wants you to accept it. I fear that your best friend may put her own feelings before any loyalty to you.
I'm afraid that this is not going to end well whatever you decide. The bravest and best thing to do is issue an ultimatum - this stops or they're both "fired". To be honest I would go further than this and dump the pair of them right now. The foundation of any relationship is trust, and you cannot trust either of these two.