Get new friends lar.. That kind of friends, are fair weather
friends. Its like, you have alot of money, these people friend
friend you, when you no money, they would even not hesitate to spit
on you. Real friends are people who standby you whether you got
boyfriend or not, neglect neglect lor, they her parents ar? Wan
your gf to greet them everytime she see them anot?
Don't give way to them, it only allows them to think they are
higher social status than you and will only time to time show some
f up attitude to keep ur self esteem low.
Show them that you don't need them, live a quality and fulfilling
life with you and your girlfriend, spike them when they see you,
don't do it purposely, just love each other more everyday. You can
most propably expect 2 things to happen, either they do more stunts
to you and your gf, or they come begging to be friends with you
again.
This method has no disadvantages. It only serve to strengthen your
r/s with your gf. Live for yourself, don't live for others.
*the above comments is a direct solution assuming you'r telling the
truth based on your story.