Transgender 'Vanderpump Rules' Star Billie Lee Shades Cast for Not Inviting Her to 'Girls Night'
24 Same-Sex Hollywood Couples Who've Tied the Knot

Billie Lee takes aim at Katie Maloney and Tom Schwartz after he calls her reaction "melodramatic."

Transgender "Vanderpump Rules" newcomer Billie Lee has been welcomed to the Bravo reality series with open arms, but when co-star Katie Maloney didn't include her in a "girls night," Billie took it as a personal attack.

On Monday afternoon, Katie, Lala Kent, Ariana Madix, Brittany Cartwright and Scheana Marie all shared the same post on Instagram -- a flyer advertising a SUR-hosted event called "Girls Night In." On Katie's post, she tagged the aforementioned SUR employees, plus alumni Stassi Schroeder and Kristen Doute -- but Katie did not tag Billie, who works at SUR as a hostess.

"Stay strong, Billie. You are light. You are love. #transisbeautiful #girlsnight," Billie captioned a selfie she posted Tuesday morning. "Thank you all for having my back through this awful time."

Katie's husband, Tom Schwartz, replied to Billie's apparent response to the situation. "Billy, this is so melodramatic. It was a simple oversight. You are loved, chill," he wrote.

But Billie did not take well to the comment and lashed out at both Tom and Katie.

"It's Billie with an IE," she began. "I was tagged hours after I said something and [was] never included in any planning. I didn't know about [the event until] Katie posted. She planned it and decided not to include me. It's girls night at my work, not her birthday party."

"You can kindly [sit] this one out, boo," she concluded, adding the hastag #namaste.

Billie and Tom did not immediately respond to TooFab's request for comment. Katie's representative declined to comment.

See the Ring! Instagram 'Vanderpump Rules' Stars Jax Taylor and Brittany Cartwright Are Engaged