@AllosaurusJei If you want to charm someone, you need to put in your best effort. It wasn't easy for Asuka, as we now saw. Humans are always acting to some degree in social interactions. Personality isn't 100% solid and fixed. You don't behave in the exact same manner in the company of your boss/junior at work, your best friend/sibling when barbecuing, a helpful neighbour you want to retain good relations with, or some snot-nosed brat who suddenly jumped in front of your bike. Yet it's all you, nonetheless. Going through the effort is not being fake, it's showing respect and dedication.
Besides, Asuka is the one who has for a long time been gaining more in their relationship anyway, in the form of his professional level cooking. She hasn't been in anger and pain while enjoying that food, prepared by the guy she likes. Kei doesn't owe her anything. If she tries to use that imaginary thing as an edge against him, then it all will fall apart real damn fast.