Hey guess what, you don't have to spend every waking minute with your girlfriend, you're allowed to have other friends, and have a life outside her.

And don't lie about where you're going and what you're doing because that will just make everything 100 times worse. Not only will it make her upset when she finds out the truth but she will continue to have zero trust in you. You need trust for a relationship and all you're doing it destroying it by lying to her all the time.

It's very simpe.. you just tell her that you're hanging out with so and so friend at such and such place tonight.

It shouldn't hurt you either if she wants to hang out with other people. At the end of the day you have to trust her that she won't do anything stupid. You should give her the same exact freedom you want.