Rule reminder
'Finché' (without 'non') = as long as — a continuous parallel condition. 'Finché non' (with 'non') = until — an endpoint. The 'non' in 'finché non' is NOT a negation; it marks the boundary. Both take the indicativo. 'Finché' = the main action is true AS LONG AS the subordinate condition holds. 'Finché non' = the main action continues UNTIL the subordinate event occurs.
Resterò qui _____ non mi dici la verità.