I'm asking about the Let's be Gems because I'm confused... Is that fanfiction that one person posted supposed to be how Dendy and Boxman Junior's relationship are supposed to be or do they have a Peridot and Jasper relationship with barely any interaction?
Um, yes and no?
While Dendydot had been Gem!Boxman's right hand Peridot, she wasn't particularly ecstatic to be assigned to help Gem!Boxman Jr. do his job.
Gem!BJ and Dendydot have more interaction than Peridot and Jasper did, but that consists of mostly of Gem!BJ ranting as he trains while Dendydot observes for Gem!Boxman.
When they captured Amko and Ruko, she was far more fascinated in studying the off-colors than the loud and obnoxious Topaz she'd been forced to babysit. (This didn't particularly help Gem!BJ's mood towards the two, particularly Amko.)
In short- Gem!BJ saw Dendydot as a friend while Dendydot saw Gem!BJ as an assignment.
So when she betrayed them, he was a wee bit bitter.