EXCLUSIVE: Erika Girardi Makes Her 'Young and the Restless' Debut With Eileen Davidson -- Go Behind the Scenes

Erika Girardi is bringing some primetime drama to daytime!

The Real Housewives of Beverly Hills star guests on the Dec. 15 episode of The Young and the Restless, and only ET was on set to capture the big day. Erika shares her scenes with her Housewives co-star, Eileen Davidson. Eileen, of course, plays Ashley Abbott on the daytime drama.

“I'm scared to death,” Erika says of acting on the iconic series. “I mean, I'm completely out of my lane!”

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Eileen gifted Erika with the role for her 45th birthday back in July. At the time, Eileen didn’t know how big of a part the show would give the “Pretty Mess” singer.

“She had to audition!” Eileen reveals. “They probably would have given her, like, one line, but they thought, ‘You know what? We'll see what she can do,’ and they auditioned her and she did so great. We did a couple scenes, and she's playing a high-powered executive.”

“Oh yeah, businesswoman fantasy,” Erika jumps in. “That's for sure.”

Erika plays Farrah, a real estate agent who has a literal run-in with Ashley. Ashley spills coffee on Farrah, and all hell breaks loose.

“I'm really, really nice, but she's a totally b**ch to me,” Erika teases. “We get in, like, a thing.”

“They pay homage [to Housewives],” Eileen says.

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Erika confesses she was nervous to go toe to toe with Emmy-winning Eileen, but Eileen says Erika totally held her own.

“She's so good, that I get to have fun,” Eileen says. “I don't have to worry about her! We're just gonna go, ‘Rawr!,’ and it's gonna be great.”

The co-stars admit it’s fun to get a little catty with one another, because they never fight with each other on Housewives. But that doesn’t mean they won’t get into tiffs with the other ladies on season seven of the Bravo hit, which returned on Dec. 6.

“Everybody’s got a lot to say,” Erika says of her co-stars, especially new additions Dorit Kemsley and Eden Sassoon.

“Everybody’s got a big mouth,” Eileen adds.

Keep up with Eileen and Erika’s Real Housewives of Beverly Hills adventures every Tuesday night at 9 p.m. ET on Bravo -- and watch them on The Young and the Restless this Thursday, Dec. 15. Check your local listings for times.

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