Post-film, Grindelwald escapes, finds and reconciles with Credence, and takes over the world. He manages to convince Dumbledore to rule with him. Grindelwald and Dumbledore keep Credence as their kept man.
Credence is still so confused. At first he thought that Grindelwald actually cared about him, but now he seems to just be using him for sex. Credence wants to hate Dumbledore, who Grindelwald clearly actually cares about. Only Dumbledore treats him with genuine affection.