Someone's Coming On to Your Mate: What Would You Do?

March 10, 2008 — -- Has anyone ever hit on your spouse or significant other?

ABC News wanted to see what people in relationships would do if they saw a stranger flirting with their loved one.

So far, the hidden camera experiment has elicited reactions ranging from good humor to direct confrontation.

And in this latest experiment, rage.

'It's Gonna Be a Long Night'

We set up the experiment at Ennio & Michael's restaurant, a cozy Italian bistro in New York's Greenwich Village. A beautiful actor named Jessie played the flirtatious waitress.

Nobody would have guessed that the first target -- sweet-looking Nikki -- would react in a more aggressive way than all of the participants combined, both male and female.

As soon as Nikki and her boyfriend -- who was in on the plot -- sat down to dinner, Nikki immediately noticed Jessie showering him with unwanted advances.

Then, as Jessie lightly touched Drew while taking his drink order, Nikki's anger began to surface.

"It's gonna be a long night," Nikki said sarcastically. She told Drew not to think she didn't notice the waitress' touch.

'I'm Gonna ... Rip Her Fingernails Out'

When Jessie came back with the drink order, she told Drew she made the Jack on the Rocks especially for him. Nikki had had it.

Speaking to Drew, she cursed like a sailor about Jessie.

"I hope you like all the hair on your head," she said. "You better shut the f-- up now because I'm gonna rip it out! I'll beat the s-- out of her if she tries to take my man."

Nikki also jokingly planned her vengeance. "I'm going to have to kill her now, you know that, right?"

Drew asked her to wait until after dinner. Even Drew acted as if he were a little worried. He half-jokingly asked whether he should take her knife away from her.

To diffuse the situation, Drew and Nikki shared a kiss even as Jessie came back and began to hit on Nikki's man even more aggressively.

As Jessie spoke to them about the menu, she placed her hand on Drew's shoulder. She then walked away from Nikki's glaring eyes and Nikki laughed ominously.

"I'm gonna f--ing rip her fingernails out of her f--ing fingertips," Nikki said.

The Last Straw?

But the waitress' flirting kept escalating. She asked Drew whether he had any tattoos, which he didn't. Then she bared her stomach to him and said she was thinking of getting one on her tummy after work and wondered whether it would hurt.

Drew said he didn't know because he didn't have a tattoo. Jessie said she would come back with their order soon.

At that point, Nikki no longer referred to the flirtatious female as their waitress -- she promptly deemed her the "skank" or "ho."

Relationship coach Donna Barnes said it looked like Nikki was letting off steam.

"I think clearly she's venting," she said.

Nikki continued to vent.

"I'm gonna pull the hair out of her f--ing head," she said.

Nikki told Drew she was trying to calm down, but if the waitress touched Drew again she was going to have to kill her.

CLICK HEREfor more reactions caught on tape!

Surprise Ending

According to Barnes, Niki's venting went nowhere fast. "Venting isn't a great, isn't an effective way to let go of anger. It's really perpetuating it," she said.

Niki's boyfriend tried to calm her down. Drew told her to tell him she loved him. Niki told him that she loved him and that Jessie's behavior wasn't taking anything away from the fact that she loved him so much. Drew offered to go to the manager, but Niki said no.

The flirting continued, with Jessie giving Drew another drink on the house. This upset Niki even more and she said she was trying to control herself. She said she was at the point where she couldn't swallow.

We decided it was time to let her in on the secret. She began laughing when she saw John Quinones approach with cameras.

"You came because you know I was gonna get her soon," said Niki.

We asked Niki whether she was ever worried about her boyfriend's loyalty. "I love him. I know that nothing would have happened. It's her I wanted to kill."

She told us she didn't go to the manager because she didn't want to make a scene.

Niki apologized to the waitress.

"I do apologize," she said. "I said nasty things about her -- that's mean, I'm sorry."

And then, something unexpected happened. In a restaurant full of people, Drew proposed to Niki. Not unexpectedly, she said yes.