While Graves is being held captive by Grindelwald, both discover that the other is his soulmate. Neither one is particularly happy about this. Grindelwald because he thought Albus was his soulmate, and Graves because he doesn't want a psychopath for a soulmate. However, they still feel an undeniable pull towards each other. Grindelwald makes Graves captivity fairly comfortable, and Graves might hate everything about the man, but he still can't help the fact that sex with Grindelwald is the best he's ever had.

After Grindelwald escapes, he tries to stay away, but still can't resist dropping in on Graves now and again. Graves wishes a part of him didn't like those visits.