Include between courses a few rounds of 'Would You Rather' questions, drawn from a jar.
(tailored to their age & personalities: funny/cheeky/deep thinking etc.)
Forfeits for passing on answering any.
Get them to create the questions for the adults.
E.g.
"...spend a night alone in a churchyard, or night alone in an abandoned castle?"
"...have night vision, or x-ray vision?"
"...Donald Trump's hairstyle, or Hagrid's beard, for the rest of your life?"
"...no tech for a week, or allow your Mum to read every email/text/tweet you send?"
"...be grounded for a month, or not allowed home for a month?"
"...be rich doing a job you hate, or poor doing a job you love?"
"...use vinegar as eye-drops, or sand paper as loo roll?"
etc. etc.