Credence taking a blast of sex pollen which loosens his inhibitions AND his control of the obscurial, making him an all-round danger to the wider area. And burnt out, post-Grindelwald, suicidally risk-taking Graves not being completely aware of the cause of the obscurial situation until he's slammed up against a wall by a desperate, horny, confused, part-smoke, part-man Credence.

Cue Graves stoically taking several for the team while being consumed with guilt over Grindelwald clearly making Credence fall in love with Graves' face. And Credence feeling horrible about everything: the sex; the repressed desire; that this isn't 'Mr Graves' but he still wants to fuck him or tear him apart or both, and that he's been forced into a situation where he can either control his dick OR the obscurus.