What if I peeked at my girlfriend's mobile phone?

It's not good for you to peek. I suggest that when you are with him, you should have the behavior of "distinguishing right from wrong" and look at each other's mobile phones together. Then pretend to overhear her chatting with her best friend to see if she got rid of it. If she didn't get rid of it, she should be very angry. I hope she can give a reasonable explanation, but not too much. She just needs to get rid of it. Personally, I think you still love her, otherwise you wouldn't check her cell phone.

If she has deleted it, don't mention it, but keep your attention in the near future, or watch your mobile phone in front of her from time to time, at least shake the mountain.

Don't quarrel directly, it won't help solve the problem.

At the same time, you should also reflect on your poor work, improve yourself, or spend more time with her, do something you want to do between you, take up her time, and don't give her a chance to get close to other boys.