It's funny how the first (only?) time Jack potentially cheats on Cass (not counting flirting with Lux as cheating) is with Danton. But I can see the obstacles to making it work on a route where Jack sees Danton as a rival, since he'd be less than sympathetic to his advances. On the willing route, Cass teasing a reluctant but curious Jack into such gimmicks, out of her own fantasy, might fit nicely. Could be a bi-curious arc, driven mainly by Cass during their shared moments with Danton, Kai and others, distinct from the current bisexual arc where Jack (also) explores his own desires independently. Existing and future scenes of the bisexual arc that are shared with Cass could be used in both.