Sandra Bullock and Chelsea Handler in a shower skit on "Chelsea Lately." (Photo courtesy E!/Chelsea Lately).

A naked and nasty Sandra Bullock welcomed Chelsea Handler to her new talk show studio on Monday by stripping off for a comedy shower scene.

The actress interrupted the host's shower at the beginning of the show to criticize her "sham" show and deliver a harsh message from TV mogul Oprah Winfrey.

As both naked stars stood face to face, their breasts pixelated, the Speed star snarled, "You have a responsibility to be a respectable talk show host. This comes directly from Oprah's mouth to my ear, to my mouth, out of my mouth, into your ear, down your body, out your vagina, up my vagina and out my a**.

"The overall theme of this message is that you are a huge disappointment. Just because your the only person on late-night television who has tiny little lady bits does not give you a free pass.

"You have a responsibility to be a role model to young girls... and you need to lay off the booze."

Slapping a stunned Handler, Bullock also urged the talk show host, who briefly romanced 50 Cent, to "stop sleeping with your guests," adding, "That is why I've not done your show; I do not wanna sleep with you."

Protesting Handler said, "I don't sleep with that many any more - just some of the rappers," prompting Bullock to slap her again, making her urinate.

The actress then snapped, "You're urinating... We don't make pee pee in showers anymore. We make pee pee in the potty."

Before walking out of the shower, Bullock paused to poke fun at Handler's naked body, adding, "All of this is disgusting. This is f**king sick. Bye."

Later during the show, Handler revealed the Oscar winner wasn't completely nude - but she was.

The comedienne said, "I was the only one who was really naked... Sandy's like, 'You can put a thong on and pasties'."

Bullock wasn't the only big Hollywood name to make an appearance on Handler's show from her Universal Studios home - best pal Jennifer Aniston was her first guest.

The former Friends star gave her pal an empty water container, explaining, "You're a big girl now... Every time you swear or sleep with a guest, you have to put money in that thing and then you want to fill it up... and then you're gonna give it to St. Jude's Children's Research Hospital."

Handler joked, "That means they're gonna get, like, a donation tomorrow... How much money do I have to put in each time I say, like, f**k?"

Aniston responded, "Let's put a hundred in there."

The actress was left a little red-faced half-way through the interview when Handler pointed out her prominent nipples, explaining, "Everyone here at work loves your nipples. Every time Jen comes on the show there's always something when her nipples are very very pronounced... Actually, I can see one!"

The giggling star shot back, "Oh jeez," adding, "Now I just gave myself chills."