Graves and Newt are dating post-film when Theseus comes to visit. Theseus has always been regarded as the golden brother, used to getting his way, used to winning. He decides that he wants Graves, and when he's refused, Theseus takes what he wants anyway. Newt finds out and assumes Percival cheated on him, and dumps him. Percival is devastated and Newt is heartbroken. Newt eventually finds out the truth and confronts Theseus and tries to make amends to Percival. Hurt/comfort please <3

+ Graves tries to fight back, but he's not fully recovered magically/physically from his captivity, making him an easy target
++ Graves tries to explain what happened, but Newt is blinded by his relationship with his brother, and refuses to believe him
+++ Comforting Tina, Queenie, Jacob, etc. believing Graves, and trying to make Newt see the truth