[Jonathan's face snaps from wariness to anger almost instantly when he raises his voice.]

You! How dare you say such things about my father!

[It takes a lot for Jonathan to break from his usual gentlemanly stride. It's hardly ever for his own preservation - no, it takes an affront against someone he cares for deeply for his hotbloodedness to truly come to the surface.

Johnny Joestar has managed to piss him off severely.]

I will not let you besmirch his noble heart! My mother...even after all those years, he never let go of the affection he held for her. He would never have even thought of doing such a thing to her memory and to our name!