The 'then you have to go' scene is one of my favorites, not only in the Luke/Jess relationship, but in the entire series. It's so powerful. I love Milo's reaction after Scott walks away, visibly breathing hard and wide eyed, absorbing the shock of it. Even though it may have taken awhile before we saw the effects of it, I really see this as the first moment in Jess's turn around, and as possibly the most important moment in the Luke/Jess relationship. For Jess, this kid who had been given no structure or boundaries, and had probably rebelled at least partially in response to the fact that his life was lacking these things, to have an adult standing in front of him who was willing to follow through on a boundary he had set must have meant a lot, and had a profound effect on him, even if he didn't fully realize it at the time. Luke was exactly who Jess needed. I get why people don't love it as much as I do though.
Anyway, 7 and 20.