One. If there is three of them, Then it really gross that he fuck the one mentality Age a like 2-4 but understandable because not only is the person (not persona ) is still dating him and the emotional situation he was in.
To be fair if they we’re real this would probably be labled as a emotional and physical abuse ( by the dad) self defense , and coping with emotional trauma/multiple personality disorder (logically that includes the sexual stuff with the other persona)
Yes I do believe this is really messed up with the child like persona but under a court of law, this is illegal sure it’s weird but it’s a coping mechanism
They’re about to start a wildfire with the sparks in between them