Min ho seemed more secure with Yuri

When Min ho found out that Kitty had a crush on Yuri just before the ski trip, he seemed more secure than he did when he met Peter. It’s like he knew Kitty’s crush on Yuri was temporary and she would find a way to create a mess out of it. But he felt insecure of Peter. It’s kinda funny because Peter is already in a committed relationship with her sister Lara Jean so how can there ever be a romantic bond between them? Also, Min ho was insecure of the relationship between Dae and Kitty, but even after catching Kitty and Yuri kiss, he was unbothered. Why is this so?