It was a perfect sunny day, and everyone was eager for summer to start, but a little unprepared for it. At the Bothell Block Party and BrewFest, some people were still sweating in jeans and boots (guilty). Sunburned suburban-dad types and UW Bothell students clutching drink tickets waited in long lines for their beer samples.

It wasn't until Chastity Belt began their set that it really started to feel like summer was finally kicking in. As usual, the band brought a mellow, languid luster to their performance, and in the heat of the sun, this super-mellow feeling was only amplified. Guitarist Lydia Lund shared an occasional smile with bassist Annie Truscott, who swayed back and forth into the rolling, easygoing rhythms she played.

Bothell Block Party was not exactly the Seattle-based post-punk band's usual crowd. There were more than few bros in the audience as lead singer and guitarist Julia Shapiro sang the lyrics to "Complain," a song from their new album, I Used to Spend So Much Time Alone (out on Hardly Art): "A couple of bros said some shit / I'm choosing to ignore." But under the hazy afternoon spell of sun and multiple little tumblers of local beer, cider, and wine, everything felt all good.

I was about five drink tickets deep myself when the band rolled up to Bothell City Hall to meet me for an interview right after Tacocat's set. Shapiro arrived on a skateboard—she and drummer Gretchen Grimm are learning how to skate, but taking it "slow and steady," Grimm said. "We're being pretty cautious about it."

Skateboarding, Shapiro explained, makes for a good tour activity during downtime in venue parking lots. "I need an activity instead of just waiting around," she said. "It's also one of those things that I have always thought would be cool to do, but it felt really inaccessible, like in the way that music felt inaccessible, as a woman, you know?"

Although Chastity Belt's members rarely if ever visit Bothell (it was Shapiro's first time here, ever), they were digging it. "Loving the cool vibes here," Lund said. "The hubbub of city life has gotten me down lately. I really appreciate this calm atmosphere, just drinkin' a couple of brews with my gals."

The band has a blackout for all Seattle shows until their album drops on June 2, but they made an exception for Bothell, which may have to do with the fact that they got a hotel room out of the deal. "I feel like I'm on vacation," said Grimm.

It's a good chance for the band to relax, and perhaps they need it. Chastity Belt's third album is full of questioning, crushing self-doubt, of racing thoughts in the middle of the night, of not feeling sure of where or who you are in the world. It's their most intense, brooding, and sophisticated work yet.

"Um... I guess we're more mature now?" said Shapiro, framing her answer as more of a question.

"Yeah, we're just growing up so fast!" Lund joked.

The band all laughs because it's a common trope they often find themselves telling music journalists, over and over again, until it fades into abstraction and doesn't even seem real to them anymore. But damn it, it's true! With I Used to Spend So Much Time Alone, Chastity Belt have expanded the depth of their signature scruffy guitar-driven sound and broadened their emotional range to create a sophisticated album seething with heart-wrenching vulnerability.

"5am," the final track on the album, thunders its way into dynamically dissonant, Sonic Youth–like glory, and the song "Stuck," written and sung by Grimm, explodes with a haunting, heavy melody reminiscent of early Lush or My Bloody Valentine. I Used to Spend So Much Time Alone feels like an assessment, a pause. Chastity Belt are at their most polished and composed here, asking—almost begging—you to sit back and consider a few things before aimlessly bobbing your head to their bright-sounding tunes.

"The narrative is that we're getting older and getting better at being in a band together. Because, yes, we are now older and, yes, we have been in a band together for years," Shapiro said in her typical comedic deadpan style.

But there's also no denying that this album is their darkest yet, masked at times with such pretty and poignant harmonies that it's hard to notice at first. The band's shared mordant sense of humor and caustic wit are still there, embedded in the lyrics, but I Used to Spend So Much Time Alone lacks the playful tongue-in-cheek jokes and ironic references found on their previous albums, No Regerts and Time to Go Home.

On "What the Hell," Shapiro anxiously intones: "If I look at my phone again, I'll just want to die / Aside from that, I feel all right." And on "Used to Spend," a testament to the powers of socializing to help you (temporarily) feel good, she sings: "I want to have some self-control / I want to be sincere / But nothing's ever really free when you're living in fear."

See? It's unsettling almost to the point where I'm torn between a motherly concern to ask if they are okay and sinking into dangerous "Why so glum, gals? Why don'tcha smile?" territory. Instead, I just asked how some of the themes of the album came together.

"We didn't really talk about it, it just... happened," Shapiro said. "I feel like since we've moved to Seattle, our songs haven't been that jokey. I guess 'Cool Slut' is kind of jokey—but it's a serious joke. I think people here actually listen to our sad songs more than when we were in college and just playing to drunk people."

Chastity Belt have come a long way from their Walla Walla days of goofing around, playing frat parties, and drinking before sets to numb the fear of failure.

"We're turning 27 this year, all of us," Truscott said. "So I think that's a big year."

"It's our Saturn returns!" Grimm laughed, almost half-jokingly.

"We're not, like, young, poppy 22-year-olds, you know," Truscott continued. "There's been some emotional turmoil for each of us."

Though it's impossible to believe that Chastity Belt will ever be one of those bands that fall into the taking-themselves-too-seriously trap, they do seem to be shedding some of the playfulness of their past for a more somber, complex way of expressing themselves.

"Fun, cool, funny... that's kind of boring to me at this point, and it's not really the kind of music that I want to listen to," Shapiro said. "Like when I put on a record at home, I want to listen to music that will make me feel something."

"It's always the sad songs that you revisit, exclusively, years later," added Lund. I Used to Spend So Much Time Alone is that kind of album—it's music that makes you feel something, and years from now, it still will.