[[ :D ]]
"I thought the meaning of that would be obvious." she said, frowning. "I still owe you, and you don't look like the type that can summon demons. So I have to follow you around," she paused in thought. "discreetly, if you want, until you think it's been paid back." she crossed her arms as she waited for him to answer.
He was lucky, even if he didn't realize it. It was rare for such a deal to be made, even more so by accident, where the demon helps on their own terms. This is why demons rarely help each other, because they'd all be in debt. Although might be honest, they have an uncanny ability to find loopholes. How did go?
"A dishonest man you can always trust to be dishonest. Honestly. It's the honest ones you want to watch out for, because you can never predict when they're going to do something incredibly... stupid."
Mages summon a demon, bind it and force it to help them in return to be freed.