Things are only made worse when a newspaper erroneously reports that Newt is engaged to his old flame, Leta Lestrange (Zoe Kravitz), which eventually leads her to start dating again (though from Waterston’s description of a deleted scene, it doesn’t sound like her new relationship was going to be established as being in the greatest place).
Newt promised that he would return once he wrote his book, but it was a promise that was broken.
Of course, if you remember the end of Fantastic Beasts And Where To Find Them you probably already guessed that none of this makes Katherine Waterston’s Tina Goldstein very happy.