Girlfriend wants me to dump my friends.?

In all honesty i love my girlfriend a lot. we just recently had our 6 month anniversery and things have been going steady but more recently she speaks about how terrible my so called friends are to me.. Honestly my friends like to hang out with my ex and my ex's best friend and yeterday at a party all my ex and her best friend did was jeer me and my friends did nothing.. one of my best friends joey speaks how they are just joking around which is bs they do it to me all the time.. my other friend devin does not see it but she hears about it and does nothing... Just last night my girlfriend gave me the choice to think about abandoning my old friends for new ones i have and if i dont she is done watching me get hurt and will break up with me.. In honesty when my friends arent hanging around with my ex and her friend its fine.. even when they are they are still nice to me... its only my ex and her best friend make fun of me and they dont say anything.. Basicly i dont know if i should dump my friends which have been my friends for years or dump my girlfriend who i love forever... idk what to do