I'm going to leave my friend at the train station.
Why would you leave your friend stranded at the train station?
He will be ok no matter what. I just don't want him to tag along with me anymore.
That is plain wrong to leave your friend stranded. You are not a good friend for doing that. I am sure the friendship will be over if you don't pick him up.
Whatever, i don't care about him anymore. He is annoying.
I am sorry that your friendship is not working out but if you told him that you would pick him up, you shouldn't leave him behind. You can end your friendship afterwards.