Eat the watermelon
Chinese net slang. You're watching the drama like it's a watermelon, but you're not getting involved. You're just there, eating and not saying a word.
I saw the whole thing, but I was just eating watermelon. Didn't want to get involved.
I was eating watermelon the whole time. I didn't know anything about it.
He was eating watermelon and pretending he didn't see a thing.