Ladies: You're trying to get your point across to a man who has never been in love for the long haul. No point continuing. He's a mysonginist to boot (i'm thinking once burnt, twice shy) so that clouds the issue even further.
Op: You're with the wrong man. Find someone who thinks like you or is willing to grow the relationship to the point where he sees your point and will willingly cut back or completely out, the one-on-one date like activities with his opposite sex friends. You're hardly a SIGNIFICANT other if the only thing that separates you from your bf's female friend is sex.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion