Over the weekend, Kylie Jenner posted a series of racy shots to her Instagram without much explanation.

According to Us Weekly, it was all part of a secret calendar project she's putting together with her beau Tyga. Exactly what photos will be used isn't known.

Over the span of a few days, Kylie shared some borderline-NSFW images. In one of the photos Kylie is topless while Tyga rests his head in between her breasts. "Happy birthday baby," she captioned the image. Another shows her smoking a cigarette while wearing lingerie.

Another shows her resting on her man's chest.

waking up this morning like ..

A photo posted by Kylie (@kyliejenner) on

"Waking up this morning like ..," she said of the image.

The images were all taken by photographer Sasha Samsonova.

Kylie and Tyga are oh-so-close in the photos, which is fairly accurate in life, as they seem essentially attached at the hip. In a recent interview with Complex magazine, she said they "need to be together at all times."

"The first year we started hanging out, everyone around him told him not to be with me. I still get comments like, 'Don't be with him.' But we're not doing it for the public — we love each other," Jenner, 19, tells Complex. "We need to be together at all times. We never get mad at each other, we just figure things out."

they don't know

A photo posted by Kylie (@kyliejenner) on

The couple first began dating while Kylie was 17 years old in 2014. They briefly split in May before reconciling.

"I just needed to see what it was like not being with him. We realized that wasn't what we wanted," she said.

At the time, Tyga said the relationship "overshadowed" his own career.