I used to have a channel 44 buddy, he always seemed to be at the field when I was or maybe I was always at the field when he was.
After a while we started greeting each other as "channel 44 buddy".
We shared the pin and there was never a problem and we both flew our planes alot.
I can see how it could be a problem if someone does not want to play nice, but fortunately in my case we were both very willing to share.