'Vanderpump Rules' SURver Scuffle: Billie Launches Attack on Katie Over 'Transphobic' Girls Night Event
How the Cast of 'Vanderpump Rules' Has Changed Since Season 1

"You perpetuating and insinuating that I'm any kind of discriminatory person -- that is the grossest extrapolation ever!" Katie shouts back.

Remember over the summer when Billie Lee started tweeting about co-star Katie Maloney not being inclusive and implying that the girls at SUR were transphobic?

Well, on Monday's "Vanderpump Rules," we finally got to the bottom of that whole debacle.

After Lisa Vanderpump fired James Kennedy (which took away his Tuesday-night gigs at SUR), Katie decided to take it upon herself to fill the void with an event she ended up calling Girls Night In. (It's kind of like Girls Night Out, except you go out in PJs. Amazing.)

Katie invited some of the girls over to her apartment to help plan the event. Apparently she didn't invite Billie because, just a few days prior, Billie approached her and Kristen Doute at SUR (while they were dining and Billie was working) to rehash the all-staff meeting they had had a few episodes back. During the meeting, Billie stood up for James, saying he shouldn't have been fired for fat-shaming Katie. Billie also blamed Kristen because her presence tends to "trigger" James.

In the days leading up to the event, Billie saw a promo for Girls Night In on several of the girls' Instagram pages, including Katie's. "It's really simple. I only tagged the people in the Instagram post that helped me plan the party," Katie said on Monday's episode. "She was on the schedule. She was invited. End of story."

But Billie took it as a personal attack and turned her sights to Twitter. "When yo co-workers don't include the only trans girl in GIRLS night at your own job! On the night you work! #rudeAF #TransIsBeautiful," she posted.

"It's the craziest thing to me! Putting it out there that we're transphobic because you weren't tagged in a f--king picture?" Lala Kent vented to Scheana Marie, who agreed that the ordeal was "becoming something that it does not need to be."

"As a child, I wasn't allowed to go to girl things because I was born a boy," Billie shared during a confessional. "I would miss out on things, and it would just make me feel like I was wrong. So I felt this rush of shame when I wasn't included."

Katie ended up tweeted back at Billie, "I'm completely supportive and will always be supportive of the LGBTQ community. EVERYONE is invited and welcome tomorrow!"

On the night of Katie's event, Billie -- who was already scheduled to work -- vented to Scheana and Ariana Madix about why she was so hurt. They heard her out, but Ariana went on to tell Billie, "You and Katie have a personal beef with each other that needs to be worked out." Then Billie decided to find Katie.

"Girl, you did not include me in any of this!" Billie told Katie, right in front of the host stand. "I've been rejected my entire life and [have not been] able to go to girls' things, and then my co-worker doesn't invite me?"

"This is for everyone," Katie replied. "This is not about that!"

Scheana then told Billie that taking her issue to social media and not to Katie personally made things worse, but Billie fired back, "#TransIsBeautiful because trans is beautiful!" She maintained she never used the word "transphobic," but she did cop to "liking" several tweets that referred to Katie and the girls as such. (We all know how Twitter works. Everyone can see what you like.)

"You perpetuating and insinuating that I'm any kind of discriminatory person -- that is the grossest extrapolation ever!" Katie shouted back.

Billie muttered "cis-privilege" before walking away to go find Lisa. ("Cis" is short for cisgender, which is a term for people whose gender identity matches the sex they were assigned at birth.)

"Cis-privilege?! Cis-privilege?! F--k that bitch," Lala shouted when Katie got back to the group, later admitting, "I don't exactly know what it means, but if it came out of Billie's mouth, I know it's f--ked up."

Fuming, Billie found Lisa and explained that she comes from "a trans experience of not being included."

"I'm trans! And it's girls night! That's my f--king pronoun," Billie explained. "I fought for that f--king pronoun, and you're not gonna invite me to a girls night or include me at all? She's not being sensitive at all."

"I hear you, but that's a separate issue, darling," Lisa replied. "These are girls that you've known for years. They organized it between themselves, and maybe there was some kind of little hiccup with you, but it's got nothing to do with you being transgender. I have never heard a word come out of any of their mouths of any negativity toward you regarding transgender. If anything, they've got the utmost admiration for what you've been through."

But Billie was on one, firing back, "She's always crying about her weight, and I'm not allowed to talk about me being trans and not getting invited to a girls night?! I cannot say, 'Oh, I can't be trans.' She can put down the food and do what she needs to do. Her feelings are hurt because someone calls her fat, but my feelings can't be hurt? She pulls her fat card. I will pull my trans card."

See what Billie told TooFab about her experience on Season 7 in the video below.

"Vanderpump Rules airs Mondays at 9 p.m. on Bravo.

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