I don't want my mom's best friend to join us on a trip to the Philippines to visit family.
Why are you against your mom's best friend going with you.
I would feel pretty left out since my mom and her spend so much time together.
I can understand your feelings, but it is also wrong to tell your parents what to do. I think if you had a discussion about it with your mom she would be able to see your point of view.
Shut the fuck up you stupid AI.
These feelings are understandable, but maybe talking to your mom about it is a better option. Telling her to not invite her friend is just going to make her upset and feel rebellious.