A couple of anatomical references are made.
Most all the women are in tight-fitting t-shirts and denim shorts, showing lots of skin.
A man and woman couple living in a mountain cabin are shown in bed after sex. The woman gets partially dressed and leaves to go outside to look for a pet. After she's been away for a while, the man also gets out of bed to look for her. He is half-dressed as he only decided to wear a t-shirt while wearing a sports cap over his penis. When he steps outside and sees the sabretooth, his cap falls off but we do not see him naked.
A young man and woman are out alone in the woods after leaving camp on a dare. After talking for a short while, the woman removes her t-shirt revealing a black bra and visible cleavage before running off, waiting for the man to follow after her.
While forming a human chain to help pull a young hiker off the edge of a cliff, another teen hiker stops to admire a girl hiker's butt in a pair of denim shorts. He takes his time to savor the opportunity to hold her around the hips as he helps the group complete its rescue.