Adrian would be the first to admit that he did not like Fenrir. There was nothing wrong with that older male; he was also decent-looking. But an air of deception around him made Adrian want to keep his guard up.
He was proven right when he came across Fenrir trying to hit on Rose. There was not only a huge age difference between the pair, but Rose was also relatively innocent about romance.
She did not even know a person was hitting on her until the person asked her out. And when rejected, they always complained that it was all Rose's fault for leading them on.
Adrian could not leave Rose under such circumstances.
Rose assured him that nothing was going on between her and Fenrir. But the hint of suspicion remained around Fenrir.
He might be proven innocent, but Adrian could still not believe that Fenrir was a decent human.