abet
uh-BETverbMeaning to help or encourage someone, usually in doing wrong
Memory hook A BET: “I bet no one sees!”. “Go on, I bet no one sees!” Rex whispers, holding the ladder steady while Pip reaches for the cookie jar. Rex abets the mischief.
The guard who looked the other way abetted the smugglers.
In context Kai did not take the cookies himself, but he abetted his little brother by holding the ladder and keeping watch for Mom.
Similar assist, aid, egg on, help
Opposite hinder, prevent, foil