Asami Sato is the daughter of a well known Equalist, Hiroshi Sato. She runs into Mako with her moped and then they shortly begin dating. Asami is a non-bender, but she's not an Equalist. When Mako starts defending Korra while she's hurt, I suspect she starts getting jealous. Then, Bolin tells Asami about Mako and Korra's kiss.
Asami is starting to get jealous!!! But she looks sad. I honestly think Asami is kind of upset, but maybe she has mixed feelings about the situation. I think she's sad and upset because she doesn't want to lose another person she loves. She already lost her dad to the Equalists. I hope she doesnt break up with Mako. That would be a huge mistake and she'll probably get depressed or something.