It is obvious to me that Chae has more knowledge of Socionics than I do, so I can only say what I think she meant. Zloty, I get the impression that you are Delta, possibly ESTJ or INFP, and from my experience, I agree that Deltas do value trust. But I think Chae is saying that for Gamma's, trust is everything. For both Delta's and Gamma's, trust is important, but if trust is violated, Gamma's Ni (single possiblity) will cause them to walk away, while Delta's Ne (many possibilities) might cause them to try to perfect or improve things. But that is just a guess.
Incidentally, I don't mind if girls I am dating also date other guys. When there is no commitment, that's not a problem. But once a commitment is made, breaking that trust is a really bad thing. Not recoverable.