Bikini Girl Still Fighting With DioGuardi, Gene Simmons Simulates Sex With Stranger | Natalie Cole Undergoes Kidney Transplant | Pop Tarts Scene & Herd

Bikini Girl Still Fighting With DioGuardi, Gene Simmons Simulates Sex With Stranger

Katrina "Bikini Girl" Darrell and judge Kara DioGuardi clearly didn't start their relationship off on the right foot as the 21-year-old sex symbol told DioGuardi off during her audition in Phoenix, Arizona. Even though the two put on a surprise performance together at Wednesday's "Idol" finale, the genetically-blessed beauties are far from "friends."

"I tried to smooth things over, but I still think she has some animosity towards me," Darrell divulged to Tarts before the show. "I don't know why, I don't hate her, I think she's pretty and a good songwriter, and we could have been friends. I was the one who reached out to her last time so now it's her turn."

PHOTOS: Bikini Girl's Before & After "Enhancement" Pics!

But during their on-stage duet, DioGuardi was the one who tried to make nice and hug Darrell several times and it was she who clearly held back and seemed less-than-impressed by DioGuardi's attempt to keep up with her sexiness with a calculated "wardrobe malfunction" in which her dress split down the front to show a black bikini.

According to an inside source, Darrell (who didn't disappoint at least visually in her bright pink bikini with two new enhanced girly assets) was very upset that DioGuardi "took over her song" and caught her off-guard on live television.

But of course, that wasn't the only drama of the night.

After his wild performance with KISS and Adam Lambert, Gene Simmons was clearly feeling the buzz and wanting to do more than just kiss as he came backstage.

"Don't I look hot?" Simmons said as he stuck out his trademark tongue (which is also body-painted) before grabbing a random good-looking young girl and thrusting her as she hugged him. Charming.

A hazy-looking Cyndi Lauper hung around waiting to talk to her KISS friends in the fellow fame world, but was only really given attention by KISS's singer, Paul Stanley. Speaking of which, Stanley started to give us some serious advice for the "Idol" contestants hoping to make it in the music biz when he was suddenly interrupted by Simmons.

"My advice is that we know where you live," Simmons said, before Stanley quietly told him to refrain from speaking as he "didn't know what he was talking about."

Some things just never change.

Natalie Cole Undergoes Kidney Transplant

After many public pleas for a donor, pop icon Natalie Cole finally underwent kidney transplant surgery at Cedars- Sinai Medical Center in Los Angeles on Tuesday and is now resting comfortably.

The kidney came from a deceased organ donor through the regional organ procurement agency, One Legacy. Cole has been receiving kidney dialysis three times a week since September, often at hospital locations around the world as she continued her world tour in support of her current double Grammy winning CD, "Still Unforgettable."

"The challenging part is having to have dialysis everywhere I go, every other day, three times a week and I have to find a facility," Cole told Tarts earlier this year. "The facility that I go to, they will research and find other facilities all over the country. It's amazing."

Ms. Cole’s physicians have advised her to postpone her summer tour dates as she recuperates for the next three to four months.

Pop Tarts Scene & Herd

Donald Trump presenting figure skating legend and former "Celebrity Apprentice" contestant, Scott Hamilton the Man of Achievement Award at the American Cancer Society "Celebration of Life" benefit in NYC last Tuesday.

Kim Kardashian at Dr. Siegal's brand new Cookie Diet store in Beverly Hills picking up a box of the diet's Chocolate and Oatmeal Raisin cookies on Thursday.

Kat Deluna and Real Housewives of New York's Jill Zarin treated to a special performance by rapper O'Neil at NYC hotspot Tenjune for the SVEDKA-sponsored graduation party for Micah Jesse on Friday.

John Legend hanging out with pals at the preview of Georgica Restaurant & Lounge at Hotel Rivington in Manhattan on Friday before heading to the penthouse to preview Hamptons’ new hot spot which will opens its doors over Memorial Day weekend.

Mariah Carey and Nick Cannon dancing together at the Greenhouse after party for "Precious" at the Cannes Film Festival on Friday night.

Jaime Pressly and Bridget Marquardt livin' it up at the grand opening of new Hollywood hotspot Jane's House on Friday night.

Perez Hilton at the Moods of Norway US Flagship Soft Launch in Los Angeles on Friday.

Paula Abdul being airbrushed by Fake Bake® at her LA home on Friday night, she then had the personal pro return for another tan on Sunday night.

Director Todd Phillips and cast from the movie ‘The Hangover’ – Heather Graham, Zach Galifianakis, Ed Helms, Justin Bartha and Bradley Cooper having lunch at Spago Las Vegas on Saturday afternoon.

"Secret Life Of An American Teenager" star India Eisley shopping at the NAPOLEON PERDIS concept store in Topanga Westfield Center in California on Saturday.

Newlyweds Mandy Moore and Ryan Adams shopping at L.A. vintage hotspot What Comes Around Goes Around on Saturday.

Haylie Duff and Emmanuelle Chriqui hosting a bachelorette party for Jenna Dewan at the Bagatelle Beach Club at the Gansevoort Turks & Caicos on Saturday. Also spotted at the Gansevoort over the weekend was Molly Sims (who was celebrating her 36th birthday) and Jack Osbourne who was seen canoeing and jogging on the beach before enjoying fresh salads and local fish and fruit from the Bagatelle Bistro.

Rock band All American Rejects at NYC Bowlmor Lanes drinking SVEDKA vodka (straight from the bottle) on Saturday night.

Retired NHL star Adam Oates dining at Nove Italiano inside the Palms Casino Resort on Saturday night.

Barry Bonds with a large entourage partying at a VIP table inside Playboy Club before moving on to Moon Nightclub on Saturday night.

Cannes Film Festival Juror Robin Wright Penn taking a short break in her day to enjoy the view from Terrazza Martini on Monday afternoon while posing for a press photo opp with a photographer for Jaeger-LeCoultre.

Paris Hilton, Ryan Philippe, Abbie Cornish, Colin Firth, Robin Wright Penn, Ralph Fiennes, Harvey Weinstein, Georgina Chapman, Peaches Geldof, Olivia Palermo, Doug Reinhardt, Julian Lennon, David Furnish, Lady Victoria Harvey, Baz Bamigboye, Martin Kemp and the cast of Nowhere Boy including Aaron Johnson, Kristin Scott Thomas, Anne-Marie Duff and Thomas Sangster at the La Plage vitaminwater house for the official after party for "Nowhere Boy" at Cannes on Sunday.

Straight after the Lakers big win Sunday night, Lakers front row fixture Dyan Cannon was spotted (with her foam finger still in hand) at Sunset Boulevard boutique KIN to check out the sneak peak launch of organic clothing line Degree 6. Also spotted was Sandra Vergara and David Faustino who played the son "Bud" on Married with Children.

Regis Philbin (wearing a lot of makeup) while eating at Michael's on 53rd St between 5th and 6th in NYC on Monday afternoon.

Elisha Cuthbert and boyfriend Dion Phaneuf relaxing at the Gansevoort Turks & Caicos and spent most of their time holed up in their room ordering food from the hotel’s Bagatelle restaurant on Monday.

Blink 182's Travis Barker, Mark Hoppus and Tom DeLonge partying with Weezer at the intimate T-Mobile party at Hollywood's Mexican favorite, El Compadre on Monday night.

Canadian model, Coco Rocha at the American Ballet Theatre Spring Gala at the MET in NYC on Monday night.

American Idol finalist Jackie Tohn performing on Monday night at Hotel Cafe in Hollywood to a crowded room which included Kristen Bell, Erika Christensen of the new NBC show Parenthood and Star Trek's Zachary Quinto.

Olivia Palermo donning Lia Sophia jewels at the Hollywood Dominos event in Cannes on Monday night.

Holly Madison having a 50 minute Muscle Melter deep tissue massage at Drift Spa at the Palms Place Hotel & Spa on Wednesday.

Carrie Underwood posing with fans outside the Nokia Theater before the American Idol finale in L.A. on Wednesday night.

Front row Lakers fixture Justin Timberlake narrating the NBA Entertainment doc Dream Season: 23 & 24 presented by NIKE highlighting Kobe Bryant's and LeBron James' pursuit of this year's championship to air on ESPN next week.

The Black Eyed Peas inking an exclusive deal with Target this week to sell a deluxe version of their new collection The E.N.D (which stands for "The Energy Never Dies") at stores and online with bonus remixes and footage.