Ghelion

A slight variation to @Summerabbacat's very interesting hypothesis: Jason and Nathan are half-brothers. Nathan's father had an affair that bore fruit , as well as a son with his wife. To prevent familial upheaval, Nathan's father offered the baby to a barren couple under the condition that the truth be concealed. Such a situation might also explain the cross-class friendship, especially if a bit of under-the-table support (or even job security) was included in the deal. But this would not explain Nathan's hesitancy (assuming he is gay). Incest? Naw...that taboo is to prevent bad genes from becoming dominant. I'm guessing that Nathan has a few secrets of his own yet to be revealed. Armchair speculation is so much fun!