Kylie Jenner is NOT cooling down for the end of the summer.

The 18-year-old reality star posted a slew of revealing poolside looks on Tuesday in NSFW Instagram photos.

WATCH: Kylie Jenner Goes Makeup-Free, Looks Like a Totally Normal 18-Year-Old -- See the Pic!

Kylie wore skin-baring black lingerie for the occasion, from Polish lingerie designer God Save Queens.

It's unclear what inspired the impromptu photoshoot, but judging from her last pic, the vibe is "happy."

WATCH: Kylie Jenner on All Her Cleavage Haters: It Means My Boobs 'Must Be Really Great'

Meanwhile, Kylie was spotted leaving a cosmetic surgeon's office on Monday, the same day she posted an essay to her website and gave her take on going under the knife.

WATCH: Watch Khloe Kardashian and Kylie Jenner's Bootylicious Dance Party

"As of now, I only have lip fillers," Kylie wrote. "Like I've said before, it has always been a huge insecurity of mine and I wanted to make a change."

"Truth is, as I've gotten older, I've gained 15 pounds and my body has changed," added Kylie, shutting down repeated rumors that she's had breast enhancement surgery.

Kylie told ET last week that she takes all the rumors as a good sign.

WATCH: Kylie Jenner Seen Leaving Cosmetic Surgery Office, Reveals She's 'Not Against' Plastic Surgery

"It's almost a compliment that they thought they were fake, because then they must be really great," she said, referring to her breasts.

However, Kylie is not opposed to getting surgery in the future.

"If, down the line, I get to a point where I’m really uncomfortable with something on my body, I’m not against changing it," she confessed.