I'm having trouble sorting out "common sweetie" , and how it is differentiated from "sweetie", "ex-sweetie" and "new old sweetie", let alone which kids go with who--and, therefore, no idea what happened or who it happened to--

Though this may all be clear in your mind, it is not clear at all to any of the rest of us--This can be a REALLY SERIOUS PROBLEM-- it doesn't matter whether we understand it here, it does matter an awful lot what teachers, counselors, law enforcement, child protective services (CPS from above, also called "child welfare"), Dept of Health and Human Services, Family Court, and other folks understand when they hear your story--

If you don't know it already, you should understand that all of the above, in certain circumstances, are required by law to respond when they hear the things you've mentioned above, even the
"Kid's Shrink" that you apparently have confided in--they may take actions, even if they don't understand the situation in the way that you do, so spend some time thinking about how to explain what has happened simply and directly (remember that even then, people often won't get it)--