CR's brother, Kenny, says it hurt to watch the slap during the Oscars broadcast because he felt helpless seeing Chris get attacked. He says the nonstop replays of the violent incident don't help either.

As Kenny told the L.A. Times ... "It eats at me watching it over and over again because you’ve seen a loved one being attacked and there’s nothing you can do about it." He added, "My brother was no threat to him and you just had no respect for him at that moment. You just belittled him in front of millions of people that watch the show."

Here's what Kenny thinks should happen to Will ... he should NOT be invited back to any other Academy Awards ceremonies, and he oughta have his Best Actor Oscar taken back.

Kenny also backs up what TMZ first reported -- Chris didn't know about Jada's alopecia.

As for whether Kenny accepts Will's apology, he said this ... "I might have looked at it differently had he initially apologized when he got on the stage and cried and accepted the award, but he didn’t, so, right there that tells me that it is something else."

Translation: hell no, he doesn't accept it. Kenny also says Will still hasn't reached out to either Chris or anyone else in the Rock family.

One last thing from Kenny ... he says Will shoulda gotten dragged outta there one way or another after the onstage hit. Kenny says, "He should have been escorted out of there,” he said. “I hold them accountable for that. He could have went up there and did anything you wanted to my brother. It could have been much worse than what he did."