Oh, that's it. She just insulted his ability not to walk. He doesn't care if this little girl is half his age, he is going to teach her a lesson in manners. Despite his lack of mobility, Ivar can still be quite fast in certain areas when he needed to be. He bats away the sword with one hand, and with the other, quick as a flash, he's got Letha by the back of her dress, actually lifting her up off the ground so that her toes barely skim the sidewalk.

He pulls out a knife with his other hand, and while he's got enough restraint not to actually hold it up to her skin, he points it at her like he means business. "I've had just about enough of you and your nonsense. Now, I want an apology for all those nasty little things you said, or I'm going to start carving runes into your skin." He won't. Probably. Hurting a child would be a new low even for the teenage Viking.