Hey Lou,
I know exactly wat your talking about... i've had friends come and go due to there new partners being insecure about me being a friend. Unfortunatly i dont argue with friends anymore, i once would of but as experiance has shown me it never does any good.
In a way, friends come into our lives for a reason, and some will always be there yet some move out of our lives for they have out grown us or us out grown them, it's the way it works in my world.
When i have a b'f on the scene, i 95% of the time still go and see my mates, even if it is under protest by the b'f, if you let them know upfront that your life has good friends whom you love and that they are just as important as everything else in ur life, then that sends a message that says i will not stop seeing my friends just because of you.
Then again sometimes people think if i see my friends when the b/f-g/f dont want me to that they will leave me. so in most cases it's both parties that are insecure, one is prob jealous and insecure the other insecure, it's just we see the new person as being the main problem.
Final words are: Everyone has choices, so people choose what they think is best for themselves at the time.
Jeez i hope this all makes sence, i'm not good at writing what i mean sometimes. so sorry if it doesn't make sence...