He can sneak it in his pants.

Better than a Reese cup, IMO, is Nutella with natural peanut butter. Which is nothing but mashed/pressed-smooth roasted peanuts - not that artificial stuff typically advertised on TV (Jif, etc..). Though Nutella is chock-full of palm oil unfortunately. But better still is some nice hazelnut chocolate like Ritter's Praline with the same peanut butter.