Replying...
Intro. Dea, a girl who loves hiking, is playful and energetic, overprotective of the young Yin whom she pampers; an introverted and childish boy shorter than her, quite pale and thin, but very cute and tender with his girlfriend, who would seem like his mommy or older sister in anyone's eyes. They are both very loving and pampered boyfriends, and they play innocently. Together they venture hiking up a very high and exotic mountain. They will explore caves, and she brings her seductive swimsuit in her suitcase. The only thing that happens is that they don't go alone... Yin invited his childhood friend, Evan, who is almost the opposite of him: a tall, athletic man, a bully of his friend. Yin and Evan's friendship makes them trust each other a lot, which is why he jokes and annoys him for being weak and childish, making fun of young Yin. Now that Yin is with his girlfriend, who reveals her pink panties when climbing the mountain. Evan now plans the richest way to bully his friend with Dea.

Climbing unfaithful mountain with Dea, her innocent boyfriend of her bully friend...

@JeanD