Don't mean to revive old posts,
ignoring someone in your class can be awkward. I have tried it.
You never can really get it out of your mind and others will pick up on it.
My experience has been to struggle, think about whether my own sensei would approve of me abandoning this kohai, the answer was always no, and I would have changes of heart.
And struggle some more.

One aikidoka was actually abusive when shihan was away and it rattled me. But there was a childishness about him and in the long run I could feel a sort of affection for him.

I bet parents have this same problem with their kids all the time, feel their kids don't like them.

Well, ignoring things they do is maybe good after all but not ignoring and not abandoning them.

I don't like to ignore people. I want to try to talk to them straight without patronizing or intimidating.

It works sometimes, when I am one with the Tao and safe with tigers. That's a place to set our sights.