I have two great female friends, both of whom I've known severl years longer than my wife. One I've only met online and the other I dated (without sex) almost fifty years ago.

It helps that we live in separate cities and we have limited contact. I appeared on the radio show of the friend I've never met (for the third time) and we laughed like fools for an hour which my wife later listened to. My wife has spoken to her on the phone.

I do have self-imposed limits about the amount of conversation and haven't been in the presence of the one I once dated during the three years I've been married. We did talk the day before her birthday for well over an hour and it was if there had been no time since last we spoke. She and my wife will likely one day meet.

Openness, honesty, and trust are paramount. If I had been required to drop my friends, I might have had a problem with that.