Your girl's friends are like family to her. More importantly, they're a group of people you want to have on your side. To show you appreciate her and her lifestyle, continually strive to know her friends better. Spend time with them, ask your girl about them, and include them in your relationship as much as you both see fit.
Your girl wants to know you like more than her - she wants to know you like her friends just as much. Disagreeing or not actively not participating in this aspect of her life is sure to set your relationship up for problems. You'll want to be compassionate and open-minded with her friends, perhaps even more than she is (always stay on safe terrain here). These are the people she will turn to for any issues with you and you certainly want them to see you in the best light. Your girl, on the other hand, wants to know you want inclusion in her entire life - not just the times you two share together.
- Rated #3 in 10 Ways To Make Your Woman Feel Amazing Everyday