Stefan grew up as a commoner in Sandpoint, but his father decided to leave the town behind when Stefan was very young. Occasionally they would settle into a new town for a time, but whether from trouble with the law, trouble with the local criminals, or Ivo's own wanderlust, they never stayed for long.
When Stefan was old enough, his father made Stefan help get money. At first, it was merely to act as a distraction, but eventually Ivo taught Stefan how to pick pockets and locks, how to read marks, and all sorts of strange tricks.
Stefan doesn't like stealing, but he understands the importance of survival, and he was proud to be able to help his dad out.
Eventually, Stefan's father built up enough courage to return home. Uncle Yim and his wife were thrilled to reunite with them, but even so, Ivo only visited for a few days at a time before taking Stefan back on the road with him.
Stefan got separated from his dad on the way to Sandpoint. Ivo can take care of himself, but it's been days with no word, and Stefan is getting uncomfortable living off the generosity of his aunt and uncle. If his dad doesn't come home soon, Stefan might have to look for some sort of income to pay them back.