How we cite our quotes: Citations follow this format: (Act.Scene.Line). Every time a character talks counts as one line, even if what they say turns into a long monologue.
Quote #1
JAMIE
You never knew what was really wrong until you were in prep school. Papa and I kept it from you. But I was wise ten years or more before we had to tell you. (2.1.55)
Here we can see clearly that Jamie and Edmund have very different roles in the family. Jamie is ten years older and, from the beginning, he was expected to treat Edmund like a baby while he was becoming an adult. You might even sense here a touch of resentment, that Jamie has had to deal with Mary for so much longer than Edmund.
Quote #2
MARY
Goes worriedly to Edmund and puts her arm around him.
You mustn't cough like that. It's bad for your throat. You don't want to get a sore throat on top of your cold.
She kisses him. He stops coughing and givers her a quick apprehensive glance, but if his suspicions are aroused her tenderness makes him renounce them and he believes what he wants to believe for the moment. On the other hand, Jamie knows after one probing look at her that his suspicions are justified. His eyes fall to stare at the floor; his face sets in an expression of embittered, defensive cynicism. (2.1.59)
Why, exactly, does Edmund give up his suspicions that Mary's back on drugs? Perhaps because real tenderness like this, which doesn't seem in any way mechanical, is in short supply in the Tyrone household. Edmund hasn't been nurtured all that much, so when he does receive affection, it's really effective.
Even more importantly, why does Jamie set his face in embittered, defensive cynicism? Sure, on one hand he's upset that his mom's back on morphine, but is that why he's "embittered"? Isn't it possible that he's jealous of the affection Mary's giving his little brother? Tenderness is in short supply around this place, and we know that Edmund gets pretty much all of what there is. In fact, there's no point in the play in which either parent is really, genuinely tender toward Jamie, and this moment suggests that he resents the lack of family support in his life.
Quote #3
MARY
It's you who should have more respect! Stop sneering at your father! I won't have it! You ought to be proud you're his son! He may have his faults. Who hasn't? But he's worked hard all his life. He made his way up from ignorance and poverty to the top of his profession! Everyone else admires him and you should be the last one to sneer – you, who, thanks to him, have never had to work hard in your life!
Stung, Jamie has turned to stare at her with accusing antagonism. Her eyes waver guiltily and she adds in a tone which begins to placate.
Remember your father is getting old, Jamie. You really ought to show more consideration. (2.1.73)
Are these really the reasons Jamie ought to respect his father? Maybe if James were a neighbor down the street – but are hard work, mortality, and monetary support the basis of a stable, respectful relationship between a son and his father? Note that Mary never uses the word "love" here. There's no question of Jamie loving James or vice-versa. Mary is, of course, right that Jamie's rude to his father, but they fail to get at the underlying issue here – Jamie can't respect and admire his father all that much because he knows him too well. These superficial traits like work, age, and money don't define who James is as a person, and so they don't define the person Jamie refuses to respect.