He hid the truth from Adam to protect him, and never revealed to him the existence of Sam and Dean, nor vice versa. Meanwhile, John trained Sam and Dean to become hunters. However, Sam later left this life to start anew in college, leading to a fallout between John and his son.
Loved: Dean and Jo\n\n She developed feelings for Dean quite as soon as they met, but it seemed clear from the beginning that while Jo was infatuated by Dean, he did not necessarily see her as much more than a sister. He was fond of her but decided to take it no further given the kind of life he led.