Seriously though, why would Al care if his parents knew he was lying? I mean, he joined the Dauntless. Obviously he's not expected to stay completely truthful at all times - if he was that, then he wouldn't have joined the Dauntless. It doesn't matter if he's truthful or not in this place, it's not like the stupid Dauntless value simple virtues like honesty in a person's character. If he was soooooo worried about them thinking badly of him, then wouldn't he have stayed in their faction like a good little Candor boy?