This year’s Sports Illustrated Swimsuit Issue is trying something completely different. Well, not completely different in that it didn’t put someone on the cover who does not look like a completely normal swimsuit model, but for the magazine’s 50th anniversary it has given us a different perspective on its cover stars.

Butts. This year is about butts.

A quick look through the history of Sports Illustrated Swimsuit Edition covers reveals a plethora of breasts. There are breasts in bikinis, breasts in chainmail, breasts barely covered by bikinis that are falling off, breasts covered by hands, breasts covered by jewelry, and even—in the case of Kate Upton—a pair of large, cold breasts peeking out of an open snow jacket in Antarctica.

The Sports Illustrated covers have been a breast-lover’s paradise for 50 years, but now they’ve turned things around and made things all about the butt instead. This year’s edition has three models on the cover: Nina Agdal, Lily Aldridge, and Chrissy Teigen. All three are topless, but aside from a bit of Nina Agdal’s sideboob, there is no breast tissue to be seen. Instead the focus is on implied toplessness and butts in tiny, brightly colored bikini bottoms. (Chrissy Teigen’s is shaped like a hot pink heart for Valentine’s Day. Aww.)

This is actually Victoria’s Secret model Lily Aldridge’s first appearance in the Swimsuit Issue, and The Daily Mail points out that a first-year model has not appeared on the cover since Heidi Klum got it in 1998.

Also noteworthy is the lack of Kate Upton. While she still has a photoshoot in the magazine, (“Kate Upton in Spaaaaaace”) this is the first year since 2010 that she hasn’t been on the cover in some way. We’re sure a lot of people miss her, but it’s probably good to change things up every once in a while so the world doesn’t get tired of seeing her on the cover.

In spite of all the smiling, tan women frolicking in the blue ocean and looking happy and beachy, this cover actually makes us really sad. Not because we’re jealous or anything, though the models obviously are extremely gorgeous, but because the tagline makes us maudlin and depressed.

It calls out “The Past,” models like Tyra and Heidi, who were the hot young rookies not so long ago. It celebrates “The Present” cover models, but in the same breath it relegates them to the past to introduce “The Future.” This year’s first-timers may be “the biggest, best rookie class in history,” but soon they will be the models of the past, too. New women will replace them, and then be replaced. Like the sands through the hourglass, so go the days of our lives.

Now we are acutely aware of our own mortality. Thanks, sexy swimsuit issue.