person A: My best friend have recently been spending a lot of time with some people from her work. 
person B: That stinks.  I always feel left out when that happens to me.  Even more so when I know the people from my best friend's work so when I can't be involved_comma_ its hard.  How do you feel about it?
person A: I am not happy  that it seems she doesn't have much time to spend with me anymore.
person B: I'm sorry.  Make sure to reach out to her and tell her how you feel.  If she's a good friend_comma_ she'll understand and make an effort to make time for you but don't let it make you bitter.