Newt's Schoolmates would have a hard time recognizing him because he's had such a radical personality shift. Newt's social awkwardness is learned behavior from being captured and tortured by many different groups of criminals doing illegal things with all those lovely magical beasts. Because if people hurt you enough times just for looking at them eventually you're just going to stop looking at people.

Unfortunately, Newt has been gone from home so long that when Theseus comes to visit his now married baby brother and old friend he thinks it's GRAVES's fault. And Theseus isn't going to leave Newt to be abused by his husband no matter how well liked/respected Graves is. Graves is absolutely furious that his old friend would even think that he might raise a hand to his husband.

Newt has an epic meltdown and eventually happy ending.