Mark, of popular YouTube prank channel The Royal Stampede, very much enjoyed making his sister briefly think his hand had been torn to shreds in a horrific smoothie-making incident, and you will too. Though Mark's sister fell for this well-executed blender prank pretty hard, as you can hear in her genuinely terrified screaming, she can at least rest assured knowing her instincts and reaction time during an emergency are very average. She didn't do too badly, but the couple of seconds she wasted being frozen in total shock definitely would've cost Mark another inch of finger.
Whether this prank boy let his sister drink that smoothie in return for scaring her is unconfirmed. But it's clearly the right thing to do.
If you enjoyed this, you can also watch Mark pretend to eat dog shit in front of strangers, which his life choices have somehow led him to do.