Chiming in.....with regard to the questions at hand....

If a sub cannot trust her Dom, for whatever reason, or vise/versa, the collar should come off. What kind of relationship would that be?? How can you call someone "friend," (and for pete's sake, "Sir" or "Ma'am") without trust?

If all is agreeable for an open relationship, why is there a fuss when one partner goes out? Because the other partner thought they could change that, maybe? Sounds like someone was dishonest in the first place, then.

Would you want to question everything in a relationship? Everything....who's that phone call from, or text? Why did it take so long coming home from work?

It gets worse, too.

Then when you break up and get into another relationship, the questions arise all over again.

Trust is the basis of all serious relationships. Sister/brother, friendships, marriage, and D/s ...

But if you can't trust, you should stop, find out why, and deal with it.