You can’t threaten them. Never mind how much trouble you got in last time, you’re outnumbered two ponies to one! Or if Simple gets involved, they might get seriously hurt!

Even knowing they won’t take it, you offer them free candy. They don’t surprise you.

Diamond Tiara scoffs, “Candy? You think you can buy our silence with candy?”
“If that’s the best you’ve got, I think revenge would taste a lot sweeter…” Silver Spoon seems to be relishing this opportunity.

At least this proves they aren’t above forms of bribery. In fact, that’s probably what they were after all along. But they’re rich. You’d have to offer something with a different kind of value. Something you can’t just buy or find.