PHOTO CAPTION: The comedian was a master of facial expression at the Orpheum. The comedian was a master of facial expression at the Orpheum. (justine hunt/globe staff)

Margaret Cho is an interesting mix of empowering friend and raunchy sex fiend. Her current tour is called "Beautiful," as in "We're all beautiful," an uplifting message but not an inherently funny one, which is why she sandwiches her short bits about loving yourself between long streams of genitalia jokes.

Cho laid her dirty comedy on thick at the Orpheum Saturday night, and the near-capacity crowd ate it up.

Dressed in a tight red-and-white striped jacket, equally tight jeans, and hot pink tennis shoes, with little or no makeup, Cho was larger than life on the video screen above her - all the better to see her masterful facial expressions. She can contort her eyes, her mouth, even her nose into the funniest positions, whether she's imitating her mother imitating Julia Child or reenacting her horrified self when a woman at an Alabama museum tells her not to take pictures because, "I know you people like to take a lot of pictures."

Opener Liam Sullivan, a former Boston-area comedian who has become an Internet phenomenon with his video "Shoes," performed by his Valley Girl alter ego Kelly, also took advantage of the video screen. He played a few short clips and then came out as Kelly in a blond wig, frayed denim miniskirt, striped tights, and fingerless gloves to perform a Canadian song that mainly consisted of the phrase, "What are you guys talking aboot?"

It's an act that might not be so funny if you hadn't already watched it a dozen times on YouTube. And it's squeaky clean compared to Cho.

The woman is fearless, and she relies largely on herself for her sex-related material. Who knows how much is true? Did she really get a collagen injection in her G-spot? Probably. Has she had as many, let's just call them unusual experiences as she implies? More than likely.

She's a big gay-rights advocate, and although she's married to a man, she identifies herself as queer ("I don't care who you are, I want you to want me"). She likes butch women - you know, the kind who rolls her own tampons - but said the lesbian cruises she's performed on, complete with Crocs fashion shows and Peppermint Patty look-alike contests, could use some work. As for the pope trying to get gays out of the Catholic Church: "No way, girl, not with all that stained glass."

She touched briefly on politics (one guess which way she leans) and ethnic stereotypes. "People come to me with Asian problems," she said, "like when they can't figure out the Sudoku. Or they need an alteration. Or technical support."

But mostly she kept it pornographic - and yet refreshingly positive. "I think everybody is beautiful," she reiterated at the end of the night, then promptly launched into a song about oral sex.