Humans are generally ignored by both sides except as 'food'- Light Fae simply taking what they need to sustain themselves while Dark Fae are more likely to kill for pleasure as well. The Light Fae generally ignore any crimes that the Dark Fae might commit against humans. Despite this, Fae parents appear to send their children to human school to ensure that they can interact with other humans, with there being no indication that Fae have a separate education system from humans.
Relationships between humans and Fae are questionable but not explicitly condoned in the short term- although Selkie are a grey area as they are mostly human without their pelts, allowing them to maintain a long-term human relationship so long as they don't use their pelts-, although Fae/human offspring are merely human with the Fae parent discouraged from making contact with the children. On at least two occasions- Geraldine and a young male Fae child-, Fae infants have been adopted by humans without the humans knowing about their true nature; although Geraldine reached puberty before her powers activated, the young boy learned about his powers while trying to help his father, with the boy and his father being 'taken in' by the Ash after the boy was discovered to preserve Fae secrets. Some prominent Fae have been shown to 'own' humans. Kristin is officially the property of the Ash, along with various other humans under his control; Lachlan (The new Ash) adheres to rules that Fae can keep their human property locked away when they aren't working, although some Fae such as the previous Ash allow them more freedom. Humans who are 'owned' may interact with Fae society and are not to be harmed by other Fae. Daire declared that Kristi Terrie was Geraldine's property to allow her such interaction. It is unclear how Fae decide what humans to 'own'; while Lauren offered obvious skills, the Ash accepted Daire's suggestion that he take 'custody' of one man just because the man had adopted a Fae child, and there has been no reference to the Ash's other human servants. So far, the only Fae shown to 'own' humans are the Light Fae, with Dark Fae servants appearing to be simply human employees without any sign that they are aware of the Fae's other-worldly natures.