In a statement to ET on Wednesday, the reality star said the joke, in which she suggested Erika Jayne was transgender and tucks her male parts, wasn't intended to offend or "belittle" the trans community.
"It was not my intention to belittle the trans community with my poor choice of words directed toward Erika. With recent news of trans women losing their lives for living their authentic truth in a world of discrimination and hate, I never want to diminish the very real pain and struggle that Trans people go through every day," Vanderpump said.
The reality star and restauranteur made the comment during a lie detector test she took on Tuesday's episode, with Vanderpump Dogs executive director John Sessa seated next to her.
"Just don’t ask me if Erika's tucking or something like that, because there are some things I can't lie about," she said, laughing.
Fellow RHOBH star Lisa Rinna quickly came to Jayne's defense on Twitter. "Who knew Lvp was transphobic? Well, we know NOW! #LBGTQ," she tweeted.
Who knew Lvp was transphobic? Well, we know NOW! #LBGTQ
Jayne has yet to speak out directly on the comment, but she did retweet transgender activist Candis Cayne's thoughts on the matter.
"Oh come on @lisavanderpump joking about @erikajayne 'tucking' Ugly Trans jokes marginalizing our community are not acceptable. Being an ally doesn’t give you a free pass To make transphobic remarks. Do better," Cayne wrote on Tuesday night.
The lie detector test was supposed to clear up Vanderpump's co-stars' accusation that she leaked a damaging story to a digital tabloid about a dog that fellow Housewife Dorit Kemsley adopted from Vanderpump Dogs. Kemsley adopted the dog only for the animal to wind up back at Vanderpump Dogs after a stop at a shelter. Vanderpump has vehemently denied the allegation of leaking or selling the story multiple times, which, in part, led to her falling out with the group.
Vanderpump opened up about the test while speaking with ET over the weekend. See what she said in the video below.