Why does my friend hang out with her other best friend

Because your friend is allowed have more people other than just you as a friend.

Trust me I know how this one feels, it hurts that she hangs out with her other best friend also and makes you feel unwanted and insignificant in her life.

She hangs around with other friends to because she cares about you both very much and likes you both for different reasons. There also may be things which she can talk to you about and not her other best friend and visa versa - not because she doesn't trust you but because different people respond to things in different ways and give different reactions so it's nice to know that there is more than one person you can tell things to so that you get the reaction you need in times of trouble.

I also imagine that she acts differently around both of you so gets to have a good time in different ways and laugh at different things. She needs both of you so don't feel to put out because you are more important to her than you think. Talk to her about how you feel and you'll see this.

Good luck x

She's friends with you both, she will want to spend time with you both either at the same time or at different times. If u go and confront her about this and use the words "why r u hangin out with her?" she may get mad because the other girl is your friends best friend. This doesn't mean she doesn't want to spend time with u, it just means she wants to hang out with you both but at different times.