I have crushes on my girlfriend's friends
What if your girlfriend and her friends hang out together, what will happen?
I'll try to find a way to follow them and hang out with them without her knowing about it
You can't help who you like, but you already have a girlfriend. You shouldn't be trying to get with other people, especially when they're your girlfriend's friend. How betrayed would she feel if you and her friend started dating?
She doesn't  care about what I do.
You might think she doesn't care, but I'm pretty sure she does. It's considered taboo to try and date your girlfriend's friends.