There's great tension between main leads and flaring passion between them. The main male lead is a go-getter, forceful and overconfident when pursuing the main female lead but there's another side to him when it comes to his girlfriend of 10 years. It's ridiculous how he lets his girlfriend control his life and make important decisions without his approval. She even doesn't work and spends a lot of his money even if they're not married yet. You can also clearly see there's no passion in their relationship anymore. On the other hand, the main female lead's boyfriend is controlling too and is rigid with his decisions and life plan. I'm not a proponent of betrayal but my goodness, I'm not totally surprised that it will happen.