It definitely feels bad to bump into the arm, enough to make Jean 'oof'. What's more, it makes him whine, since he wanted to go into the shiny portal-

But when he notices who it was that stopped him, he gets some clarity out of his wolf cub impulses. "Ga-Ah--! Levi!"

His ears are now drooping because he's ashamed of how he was acting just a few seconds ago. And also because, whoops, he never told about... well, this.

"I can explain..."