Is it that "Ik mag niet mee" means only "I am not allowed to go with" (meegaan) or also "I am not allowed to come with" (meekomen) or "I am not allowed to sing with" (meezingen) or some other "mee" nouns? Generally, without a context, it is impossible to say, what it refers to.
Hi quollism - where do you come from? I've honestly never ever heard anyone say "do you want to come with?" Fascinating! I've just googled it and came across this forum which is worth a read if you've got time to kill!