Love Island USA spoilers: Kyle disappears, couples split. Here's what you missed in Week 4

During Week 4 of "Love Island" USA, the men and women weathered the ultimate relationship test that is Casa Amor, one longtime couple became exclusive and two islanders unexpectedly left.

Twelve newcomers arrived last week to shake things up, and that's exactly what they did — so effectively, in fact, that several couples started questioning their relationships, and one Day 1 couple split during the post-Casa Amor recoupling. However, the experience only made another Day 1 couple stronger.

Here's what happened on Episodes 20-25 of "Love Island," which aired Aug. 9-14.

Week 3 recap: New arrivals make one islander 'hope the kitchen burns down'

'The human centipede of regurgitation' at Casa Amor

In Episode 20, the first night of Casa Amor continues with Jesse Bray hyping the men.

“I wanna have a blast. I wanna have fun with it,” Jesse says. “This is the vacation from what we’ve got back at home. Let’s not forget about what we got back at home.”

Chazz Bryant and Gabby Kiszka start gravitating toward each other — as do Phoebe and Isaiah.

Jeff is open to getting to know the women, but “something really gotta hit it off for me to stop thinking about Nadjha (Day),” he says.

The producers arrange for the islanders to get to know the 12 newcomers by passing liquid to each other via their mouths — “like the human centipede of regurgitation,” as Jared describes it — in the Shaken and Stirred challenge.

After passing various cocktails mouth to mouth until the glasses are filled, the villa wins. Their prize? Bragging rights, maybe?

Deb finds passion she’s ‘lacking with Jesse’

On day two of Casa Amor, the islanders realize whom they are and aren’t attracted to.

After sharing a bed with Tre Watson, Nadjha concludes that there were “no sparks flying anywhere” and sets her sights on Nic Birchall, who is “the first person that I’ve been excited about.”

Courtney Boerner also realizes there isn’t a connection between her and bed mate Jordan Morello: “I just don’t think he can handle me,” she says.

Deb Chubb, however, finds that she’s open to Kyle Fraser, who promises to bring the passion that she’s been looking for.

“I think (Kyle) kind of, like, has everything that I’m almost lacking with Jesse,” Deb says.

Over at Casa Amor, Jesse isn’t as interested in finding a potential new partner.

“In the back of my head I’m just thinking of Deb,” he says in an interview.

Sydney Paight is also not entertaining any of the new men because “I just really miss bae, and I hope he comes back to me.”

Week 2 recap: Courtney's breakup fallout and Andy's 'blatant disrespect'

Isaiah says he and Sydney were ‘missing something’

After an afternoon spent competing against the villa in the Raunchy Races challenge, Casa Amor wins a party as well as a night in the Hideaway. Though the Casa Amor women want to send Phoebe into the private suite “to break Isaiah,” Chazz and Gabby end up being nominated to christen the Hideaway.

Though Isaiah shared a bed non-romantically with Chanse Corbi the first night and had intended to ask Sydney to be his girlfriend on their next date before Casa Amor caused an interruption, he finds himself interested in Phoebe in Episode 21. Casa Amor is the ultimate test, after all.

“I came in here with my boxes checked, but I was missing something. Right now, (Phoebe has) definitely checked an extra one off,” Isaiah says.

Sydney has all the time in the world to worry about what Isaiah is doing while they’re separated. She and Zeta agree that their partners cuddling with other women would be a dealbreaker for them. If Isaiah returns to the villa single, Sydney wants to ask him to be her boyfriend.

“I’m risking it all for that man,” Sydney says.

In Episode 22, Phoebe tells the Casa Amor women that she wishes Sydney finds someone “that’s, like, hotter than (Isaiah).”

Here’s who was coupled up after Casa Amor

After spending alone time in the Hideaway, Chazz decides to pivot away from Gabby in Episode 22.

“I much rather would have gone into the Hideaway with you,” he tells Bella.

Jeff also comes to the realization that he’s interested in someone else — someone who’s not even at Casa Amor. He reveals that he wants to pick up where he and Nadjha had left off; she’s someone to “take … home to mama,” he says.

After nearly four days apart, the islanders are forced to make up their minds. Will they stick with their previous partner or bring someone new into the villa? Here’s who coupled up after Casa Amor.

• Courtney and Chad.

• Chazz and Bella.

• Jared and Chanse.

• Nadjha and Nic.

• Zeta and Timmy.

• Deb and Kyle.

• Isaiah and Phoebe.

Kat, Jeff, Jesse and Sydney are left single after the people they wanted to be coupled up with chose other partners. Jordan Morelle, Sam Kornse and Tre as well as Gabby, Tigerlily Cooley and Avery Grooms are sent home.

“I’ve realized how I should be treated in a relationship, and I’ve realized what I deserve,” Deb says as she chooses to recouple with Kyle.

“I always told her, you know, you deserve better than me. At the end of the day, I just want to see her happy,” Jesse says after finding himself single. “I’m happy with my decision.”

Isaiah brings Phoebe back — but he's still ‘70% for’ Sydney

Sydney did not react as calmly as Jesse did to the news that Isaiah came back with another woman.

“I feel like I was just hit with a semi-truck. I feel very betrayed. I just thought what we had was more than that, but I guess I was wrong,” Sydney says. “I’m just really sad right now but I’m not crying this … makeup off.”

In a twist, it turns out that Isaiah had chosen Phoebe not because he intended to pursue her but instead because he hadn’t fully made up his mind.

“I’m definitely 70% for Syd and 30% for Phoebe,” Isaiah tells Nadjha in Episode 23.

After some consolation from her friends, Sydney agrees to debrief with Isaiah.

“Of course I’m shook, but of course I want you to be happy,” Sydney tells Isaiah.

Jesse and Deb are also in limbo; seeing Jesse return alone “made me fall for him more,” she says in an interview. They ultimately have a reuniting kiss, though she still shares her bed with Kyle that night.

There are a whopping 18 people living in this villa after Casa Amor — but this doesn’t last long because two men end up abruptly leaving.

Q&A: 'Love Island' veteran Iain Stirling on voicing UK vs. USA shows

What happened to Kyle Fraser on ‘Love Island’ USA?

Kyle is there one moment and gone the next.

Thirty-five minutes into Episode 23, narrator Iain Stirling buries the lede when he announces, “It’s nighttime, and Kyle has left the villa for personal reasons.”

Viewers who caught this may have been confused about this mysterious development. The Arizona Republic has reached out to “Love Island” representatives for a statement about Kyle’s departure.

A quick check of social media reveals one potential reason for Kyle no longer being on the show.

On Aug. 9-10, an Instagram user named @kelly_themodel alleged that Kyle sexually assaulted her and gave her chlamydia. She went on to share screenshots of similar anecdotes from anonymous users.

It’s unclear whether the allegations are connected with his disappearance from “Love Island,” and as of Aug. 15 Kyle has not responded to the allegations on social media.

Nadjha and Jared leave their Casa Amor partners; Nic leaves

Like Deb did with Kyle, Nadjha also starts reconsidering her Casa Amor couple. Ultimately, she tells Nic that seeing Jeff return single “really made me feel a type of way that I didn’t think I was going to feel,” and she realizes that she has feelings for Jeff after all.

After he’s rejected by Nadjha, Nic self-eliminates in Episode 25, telling the islanders, “I’ve had the best experience I could ever ask for, and I think I need to be home with my family.”

Another islander, Jared, also strays away from his Casa Amor couple. Kat took a risk by refusing to couple up with anyone during Casa Amor, and it pays off when Jared reciprocates her interest. That night, he shares a bed with Kat outside instead of staying with Chanse.

Chanse, who was surprised by the bed arrangement, finds Kat “swooping in and stealing him” shady.

Sydney feels ‘so disrespected’ by Isaiah

Jared rejecting Chanse isn’t the major drama of the night, though. No, that’s the long-awaited conversation between her and Phoebe, which both of them are dreading.

“She deserves to hear every detail that occurred between me and Isaiah that she respectfully deserves to know” Phoebe says in an interview.

In Episode 25, Phoebe tells Sydney about the times she cuddled and made out with Isaiah during Casa Amor. The visuals end up being too much for Sydney to handle.

“I’m not this girl, like, I’m just so disrespected,” Sydney later tells Zeta in between sobs.

Isaiah reveals that though he did see “a little something between (him and Phoebe),” it ended up being “a big reality check” that showed him his true feelings for Sydney.

So it becomes time for Isaiah to grovel to Sydney: “My heart is for you” he tells her. He issues the full apology the next day: “I cannot be more sorry for what I did to you. I know you don’t deserve that.”

“Sydney, my options are closed. I’m all for you,” he tells her.

However, Sydney’s trust has been broken, and she’s not sure if she can go back.

Timmy and Zeta become exclusive

After four weeks, Day 1 couple Timmy and Zeta are finally sent on their first date. The duo rides a tandem bike and pots some succulents in a greenhouse with the goal of building the foundation of a strong relationship.

“I see you in my life outside the villa 100%,” Timmy tells Zeta. “I feel like you’re my person, so I would like to be very exclusive with you outside of this.”

She readily accepts and gushes in an interview that she “definitely could see it turning into love.”

After they return, it’s time to cull some of the singles. Jesse couples up with Deb, who was left single after Kyle left, and Jeff chooses Nadjha.

This means Kat and Sydney are left single “and vulnerable.”

But wait, who’s that walking in? We’ve got another bombshell — Joel Bierwert, a 27-year-old welder and fabricator from Northampton, Massachusetts.

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What time does 'Love Island' USA air?

New episodes of "Love Island" USA Season 4 stream starting at 6 p.m. MST (9 p.m. Eastern Time) Tuesdays-Sundays on Peacock. Saturday episodes recap the week and show unseen clips.

Reach Entertainment Reporter KiMi Robinson at kimi.robinson@gannett.com. Follow her on Twitter @kimirobin and Instagram @ReporterKiMi.

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This article originally appeared on Arizona Republic: Love Island Season 4 recap: Breakups and an islander vanishes