Pinkett Smith’s expense

He doesn't even need to! Will's actions along make him a far better target for what comes next.

Chris can just walk on stage, pull out a safety helmet, put on, then say:

"And now for the Jada Pinkett Smith joke."

That's all he needs to do. There doesn't need to be any actual joke that follows nor does he need to directly reference her ever again because this dumbass stunt is more than enough to repeatedly point out how much of a complete moron Will is.