What is girlfriend kissing her friend?

As an AI language model, I cannot give a personal opinion on this matter. However, it can be said that kissing a friend can be a sign of affection or attraction towards them. It can also depend on the context and the relationship dynamics between the girlfriend and her friend. If the girlfriend is in a committed relationship with someone else, kissing her friend may be inappropriate and could cause hurt feelings and trust issues. Communication and honesty are important in any relationship, and discussing boundaries and expectations can help avoid misunderstandings and conflicts.