We're not on Wisteria Lane anymore.
"Desperate Housewives" (search) star Felicity Huffman donned a plastic penis — and lowered her voice four octaves — to play a male-to-female transsexual in "Transamerica," (search) premiering this weekend at the Tribeca Film Festival.
In this road comedy — executive-produced by her husband, actor William H. Macy (search) — Huffman plays Bree (aka Stanley), who's living as a woman awaiting her upcoming sex-reassignment surgery.
When Bree learns she has a 15-year-old son from a long-ago tryst, her doctor insists she bail the boy, a male prostitute, out of jail.
But the uptight Bree doesn't tell her son her true identity (sexual or otherwise) as they take a cross-country car trip back to Bree's home in California.
The son finally has a "Crying Game" moment when he spies Bree urinating.
Huffman, outfitted with a plastic appendage she named Andy, said she filmed the scene with "this water bottle duct taped to my ribs with tubes attached to Andy.
"And I'm already wearing really tight underwear with pantyhose and a girdle to pack everything in," Huffman said. "All this took two or three hours in the middle of the Arizona desert!"
The 42-year-old New York native was offered the role just before shooting the pilot for "Desperate Housewives," on which she plays a woman who puts her career aside to raise four unruly sons.
"I initially tried to talk the director, Duncan Tucker, into casting a man for the 'Transamerica' part," she told The Post. "But he told me, then it would be a movie about a man in a dress. It's not about what's under my skirt, but about being shy and alone, things anyone can relate to."
For Huffman, the most difficult thing was Bree's deep voice. She worked with two coaches, one of them an expert at coaching men to talk like women.
"I had to find the voice each day, and it was so difficult, I had to keep it until the end of the day's shooting. My husband was freaking out when he called.
"He finally said, 'I just can't talk to you in this voice, it's too weird,' " she recalled with a laugh.
She even had a "Tootsie" moment on the phone with her agent, who thought she was a male prankster.
She's so convincing that there was initially talk about "Transamerica" being released without revealing the main role was played by a woman.
"But the success of 'Desperate Housewives' made that impossible," Huffman said.
"People are even starting to recognize me on the street."