Amazing film.
Emily's issue was that she wasn't reading the mood of the room. She would walk into the house in a cheerful mood while Luke is working so hard trying to prove that he's good enough. She would try to help Luke by helping him get promoted but he didn't want that. He wanted to earn his promotion which wasn't going to work unfortunately.
Luke's issue was that jealousy got to him. At first I didn't blame him because he was working so hard but wasn't being heard, he wasn't being given the opportunities but later on, he took that anger out on Emily when she supported him a lot.
Started off with both Emily and Luke being happy with their jobs and relationship. When Emily was given the promotion that Luke was hoping to get, he was happy for her.
But everything changed when Emily asked Luke why he was behind in processing some market shares. Emily didn't mean it in a wrong way but Luke felt like that was the case.
Things got worse when Luke asked Emily to trust him in investing in some company which went badly. Emily then had to make up for it and chose her gut instinct which worked for her.
The usual thought popped up for Luke when he said Emily got the job because "she ticks the boxes" and because she was doing personal favours for Campbell and not because she deserved it. Jealousy got to him. It started for him because he felt as though he wasn't being heard initially but then towards the end, it was pure jealousy for what Emily achieved.
The final scene was great, Emily wanted Luke to know how she felt since she got the promotion and for him to take responsibility for his actions. It felt weird that she had to stab him to force him but it worked.