My girlfriend's good friend sent me a text message saying that she likes me. What should I do?

In fact, you already have the answer yourself.

You said that you love your girlfriend very much, so no matter how beautiful this classmate is, don't change your mind. On the one hand, you should consider your relationship with your girlfriend. On the other hand, you should decide whether to tell your girlfriend about it or not. When your girlfriend finds out, it will definitely affect these two good friends. You should refuse her. It is necessary! Otherwise, it will only leave a curse. If you don't show your attitude like that, your girlfriend will know the relationship between the two people sooner or later, and the consequences will not be ideal! So you should hurry up and make a quick decision, which can't be pushed. Trust me! (provided that you love your girlfriend very much)

This is just an episode between you and your girlfriend! There is still a long way to go!