David and Shannon Beador have taken steps to heal their marriage. During the 10th season of "The Real Housewives of Orange County," Shannon revealed that her husband had an affair with another woman, who also happened to be married. And while the two have been going to counseling sessions and appear to be doing much better, this weekend, Shannon had a run-in with her husband's former mistress at a university football game.

Entertainment Tonight reports that according to a source, the couple was at the USC Trojans' football game at the Los Angeles Memorial Coliseum on Saturday, Oct. 24. The insider said that David's ex mistress Nicole McMackin and her husband Reed were only about 15 rows in front of where Shannon and David were seated. The reality star reportedly started yelling while the teams were practicing, then an argument allegedly started when Nicole and her friends were walking through a tunnel to return to their seats.

In an interview with People, Shannon said that she could not understand why Nicole and her husband couldn't sit somewhere else.

"We're boosters," said the reality star. "We've had this tickets for 10 years in the same place. They were aware of that."

In the tunnel during halftime, Shannon said that she had a confrontation with Nicole, and Shannon told People that she "very calmly" said, "You have a lot of nerve being here Nicole."

The mother of three said that Nicole screamed at her face and cursed her out, and that's when she got angry.

"I got angry and screamed to the stands, 'This is who my husband had an affair with!'" the Bravo star told the magazine.

Shannon also took to Instagram over the weekend to post a picture of her with David and their friends at the game and wrote, "Someone with no moral compass decided to show up again."

Meanwhile, Reed McMackin released a statement to Entertainment Tonight.

"This has been an extremely trying time," he said in the statement. "Nicole knows that she has done a terrible mistake and there has been an incredible price paid by both families."