Kylie Jenner Flaunts Sideboob In Sexy Swimsuit On Birthday Trip, Joins Kendall Jenner On Tea Detox Diet [Photos]

Kylie Jenner had an 18th birthday blast that included her sister Kendall Jenner, boyfriend Tyga, and pals Hailey Baldwin and Pia Mia. And Kylie proved that less is more when it comes to swimsuits by choosing a one piece with minimal fabric to show off her gorgeous skin, reported Us Weekly.

Sunning on her birthday trip in Punta Mita, Mexico, Kylie flaunted cornrows for a hairstyle that didn’t detract from her bathing suit, which seemed designed specifically to flaunt her sideboob.

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“relax w meee,” wrote Jenner in her Instagram caption.

To make it even more fun, Kylie, Tyga, Kendall, Hailey, and Pia took off on jet skis and went wild on a yacht.

But Kylie got even more attention when she did a who-wore-it-better closet theft from Kris Jenner and donned a to-do-for Body Glove one suit in bright pink, reported People.

Kris shared that the 80s-style suit was one of her old favorites, showing that in the fashion world, everything comes around if you wait long enough (and use a lot of mothballs).

Jenner showed her sense of humor in her caption for the photo.

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“Ohhhhhhh so THIS is where my vintage Body Glove bathing suit went!!!! @kyliejenner you are grounded! Wait, I can’t do that anymore you’re 18….#whoworeitbetter #80’s #whoknewyouwouldlikemyoldstuff #recycle #love #mexico #alcapulco1989,” wrote Kris.

So how did Kylie get that fabulous figure to flaunt in her swimsuit collection? Jenner went on a new diet after gaining weight, reported E News.

“I’m working out and I’m eating a lot better,” said Kylie. “Well, I didn’t realize I was lactose intolerant. I just became lactose intolerant like, this year. And I love like, cheese and everything so I’m so mad but, I dunno, I just, it was my year to eat bad. I was like, while I’m young, I might as well. I didn’t care about a diet or anything. But now, this last month, I’ve been working on it just for health reasons only.”

As the Inquisitr reported, Kylie also joined Kendall on a so-called “teatox” diet. These detox diets involve drinking a special tea reported to boost weight loss.

In addition to working out, Kendall relies on detox tea.”I usually start my day off with a cup of detox tea,” said Jenner. “I have like 12 cups a day.” “She wants desperately to be taken seriously as a model,” said a source. “And if it means starving herself, she’ll do it.”

As for actual food, Jenner does eat, but it’s primarily veggies, said another insider.

“During a recent family dinner, Kendall ordered just a bunch of raw veggies and nibbled on them,” revealed the source.

[Image Via Kylie Jenner/Instagram/Jason Merritt/Getty Images]