When Justin Timberlake and Jessica Biel fell in love, they had no idea how many challenges would soon come their way. Since 2007, they've had many highs and lows.

One of the biggest issues the high-profile couple has faced is Timberlake's alleged serial infidelity. The "Sexy Back" singer hasn't just had a few exes before dating Biel. He accumulated a couple of exes while dating Biel and after they were married too. Some are rumors, including one fling with X-Men: Apocalypse's Olivia Munn, and more recently, his Palmer co-star, Alisha Wainwright.

That scandal threatened their marriage unlike anything else, but Biel eventually forgave her husband for the slip-up, as she has with others, following his public apology. Now Biel's back to gushing about Timberlake; they took a romantic trip to rekindle the flame between them and had a secret COVID baby.

Biel and Timberlake might be on better ground now, but the fact remains that Timberlake has been unfaithful in the past, and he's had to deal with the regret every day, making amends to his wife.

What Exactly Happened Between Timberlake And Munn?

In October 2010, Us Weekly came out with an explosive exclusive report claiming Timberlake had gone on a three-day fling with Munn in September of that same year.

They met on September 26 at a MySpace event, exchanged numbers, and Timberlake "started chasing her immediately," an insider claimed. Apparently, Munn resisted the singer's advances and said there wasn't a chance between them if he was still with Biel.

Related: 15 Low-Key Facts About Justin Timberlake And Jessica Biel’s Marriage

But, in a sneaky move, Timberlake started "telling people it’s over with Jessica, even though the reality is he's just doing it behind her back." Munn believed the lie and took him to her hotel, the Gansevoort Park Avenue in New York City, for a couple of days, where "they were openly affectionate" and "had amazing sex" that night. Timberlake's team strongly denied everything.

Later, a source "close to Munn" told People that the allegations were false. "There is no truth to the reports. Olivia Munn is not that type of girl," they said. Another source claimed that "Justin and Jessica are doing fine."

But they clearly weren't doing too fine because they split in February 2011, after three years of dating. They did reconcile three months later, however, and got married in October 2012. They welcomed their first child, their son Silas, in 2015.

Trouble Again, This Time With Alisha Wainwright

The disaster that was the Munn scandal proved to be a walk in the park compared to a scandal that came nine years later. In November 2019, leaked photos showed Timberlake being really comfy with his Palmer co-star, Alisha Wainwright.

"They all know each other and were hanging," a source told People. "Like, come on, they’re on an open balcony in New Orleans, and he’s famous. It was nothing."

A source shared with E! News, "They are downplaying everything and trying to laugh it off as nothing. But it was definitely inappropriate and something that would make any wife uncomfortable. He had too much to drink and got carried away."

Related: This Is What Alisha Wainwright Thinks Of Justin Timberlake

This time, Timberlake broke his silence and took to his Instagram to send out a public apology. "I drank way too much that night and I regret my behavior. I should have known better," he wrote. "This is not the example I want to set for my son. I apologize to my amazing wife and family for putting them through such an embarrassing situation, and I am focused on being the best husband and father I can be. This was not that."

Sources continued to way in on the scandal by saying Timberlake and Biel's marriage "will survive. He feels guilty and will make it up to her. She is very good to him, and he knows how lucky he is. He says it was not a big deal, they were all hanging out together, and that's the end of the story."

Munn Has Faced Backlash

Years after her alleged scandal with Timberlake, Munn has continued to face backlash and has been labeled a home-wrecker by some fans.

The incident that may never have happened is once again being brought up now that Munn is seemingly in a relationship with John Mulaney. They've been linked since around the time that Mulaney announced he was divorcing his wife, Anna Marie Tendler. So the suspiciously close timeline has spurred fans to think that she helped ruin Mulaney's marriage.

Related: Olivia Munn Denies Rumors That She Is Dating John Mulaney

Fans on Twitter resurfaced the drama with Timberlake and blamed her for "causing drama" with people's marriages.

"When has Olivia Munn ever not caused drama? Oof I think of all the drama she’s caused (men) over the years," one fan wrote.

"John Mulaney needs to just focus on his recovery right now, he just filed for divorce like 5 seconds ago and his wife is still in shock. This is gonna end messy folks," another added.

"Well she’s good at getting boyfriends to stop talking to their friends and family we know that lol, and sounds like this guy needs his family now more than ever," another said.

"Olivia ‘Lisa’ Munn, breaking up marriages and relationships in #LAcounty since 2004. #oliviamunn #notaniceperson," another bashed Munn.

If the allegations are false and Munn never even talked to Timberlake, it would be unfortunate for both parties. But the fact remains that Timberlakes has been seen with a couple of different women in incriminated circumstances while he's been with Biel. So it's safe to say he probably regrets a lot, not just being seen with Munn. Only time will tell if he can keep his relationship with Biel afloat, but it's best to steer clear of rumors.

Next: Jessica Biel Trolled For Not Supporting Justin Timberlake After Appearing On Ellen