He's acting as if he doesn't know his brother at all.
"How could he possibly abuse you?", says the guy who suffered because of that sack of shit.
This is fucking stupid.
Like, colossally stupid.
Because of the pair thing he should be prioritising Rubelina's safety, and the easiest way to do that, would be to leverage his position. He knows that she's a magician on par with the Crown Prince, since one needs to be on a similar level as their pair, but he doesn't consider for a moment, that that alone, puts them on a collision course with the Head Clown.