Nothing fires up the internet like a shocking, crazy or surprising celebrity couple.

From Kim Kardashian and Pete Davidson to Jennifer Lopez and Ben Affleck, these celebrity couples really stunned the internet when they got together.

Here's a look back at all the romances that had everyone talking in 2021:

Kim Kardashian, Pete Davidson

Kardashian and Davidson first sparked romance rumors after the two were spotted at a theme park together following the reality star's appearance on "Saturday Night Live."

After attending a few dinner dates together, the two celebrated the comedian's birthday in the company of Kardashian's mom Kris Jenner and rapper Flavor Flav, according to Instagram. The group posed for a photo, which was later posted by Flavor Flav.

The day after the birthday celebration, Kardashian and Davidson were spotted briefly holding hands during a stroll in Palm Springs sending the internet into an uproar.

Kardashian has been single since filing for divorce from her estranged husband Kanye West in February.

Kim Kardashian and Pete Davidson as Jasmine and Aladdin on SNL

Kim Kardashian and Pete Davidson first sparked romance rumors after the reality TV star appeared on "Saturday Night Live" in early October. (YouTube/NBC ‘SNL’)

KIM KARDASHIAN AND PETE DAVIDSON: A TIMELINE OF THEIR RELATIONSHIP

Jennifer Lopez, Ben Affleck

Lopez and Affleck set the internet ablaze when they revealed they had rekindled their romance.

The "Hustlers" star and "Argo" director were previously engaged for roughly two years. The two split in 2004, and Affleck later married actress Jennifer Garner in 2005. Affleck and Garner, who share three children together, divorced in 2018. Meanwhile, JLo married Marc Anthony. The pair went their separate ways in 2011. They share two kids together. 

Fast-forward to 2021. Lopez confirmed she and Affleck had rekindled their relationship in July after she shared a photo of the two kissing on Instagram. Before the kissing photo hit the internet, Affleck and Lopez were continuously talked about as they were spotted traveling and spending time together by paparazzi.

Jennifer Lopez and Ben Affleck

Jennifer Lopez and Ben Affleck rekindled their relationship earlier this year and confirmed their romance in July. (Gotham/Wireimage)

Kourtney Kardashian, Travis Barker

Kourtney Kardashian's relationship with Travis Barker is another love fans just can't stop talking about.

Kardashian and Barker first sparked romance rumors at the end of 2020 but didn't publicly confirm their relationship until February 2021. The couple is known for posting PDA-filled photos on social media.

Barker asked Kardashian to marry him in October during a lavish proposal. The engagement ring is estimated to be worth around $1 million.

Kourtney Kardashian and Travis Barker

Kourtney Kardashian and Travis Barker confirmed their relationship in February and were engaged by the end of October. (Jeff Bottari/Zuffa LLC)

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Shailene Woodley, Aaron Rodgers

Shailene Woodley and Green Bay Packers quarterback Aaron Rodgers' relationship took the internet by surprise. It seemed like nobody was aware the two were even dating until news broke that they were engaged to be married. 

Rodgers first announced his engagement to Woodley in February 2021 while receiving his NFL MVP award. Woodley later confirmed the couple's engagement while appearing on "The Tonight Show Starring Jimmy Fallon."

"Yes, we are engaged, we are engaged," Woodley told Fallon at the time. "But for us, it's not new news, you know, so it's kind of funny, everybody right now is freaking out over it, and we're like, 'Yeah we've been engaged for a while.'"

Shailene Woodley Aaron Rodgers

Aaron Rodgers and Shailene Woodley confirmed their engagement in February. (Getty Images)

John Mulaney, Olivia Munn

Comedian John Mulaney and Olivia Munn shocked the internet when the two revealed they were dating and expecting a child together in September 2021, months after he filed for divorce from Anna Marie Tendler.

Mulaney officially filed for divorce in July 2021, but the couple originally announced they were separating in May.

The internet has speculated that Mulaney allegedly cheated on Tendler with Munn. The actress addressed the rumors but decided against giving a timeline to correct the online narrative.

"They think they know our relationship so well. When, in reality, they don’t," Munn told the Los Angeles Times. "There’s no way anyone could know what any of his relationships were or what our relationship is."

John Mulaney and Olivia Munn

John Mulaney confirmed his relationship with Olivia Munn in September. The comedian also revealed he was expecting a child with her. (Getty Images)

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Kanye West, Irina Shayk

Although it wasn't ever confirmed the two were actually dating, Kanye West and Irina Shayk's short-lived alleged romance also took the internet by surprise.

West and Shayk were first spotted together in June. The two traveled to France to celebrate West's 44th birthday and had reportedly spent time together before the trip as well.

"She seems smitten," a source told People magazine at the time of the trip. "He invited her to France, and she happily accepted. They are not officially dating, but there is an interest from both sides."

However, by August the fling was apparently over.

"It was never a serious thing that took off," one source told People magazine.

Kanye West and Irina Shayk

Kanye West and Irina Shayk's relationship was never confirmed, but the two first sparked romance rumors in June. (AP/Getty Images)

Renée Zellweger, Ant Anstead

Renée Zellweger and Ant Anstead made headlines as they were spotted spending time together in June 2021. The new relationship came months after Anstead finalized his divorce with ex-wife Christina Haack in September 2020.

Haack also didn't waste any time. She revealed her new relationship with now-fiancé Joshua Hall in July 2021.

Renée Zellweger and Ant Anstead

Renée Zellweger and Ant Anstead were spotted publicly for this first time in June. (Getty Images)