LAS VEGAS — Lisa Vanderpump had plenty to celebrate Saturday night at the opening party for her Vanderpump Cocktail Garden at Caesars Palace in Sin City, but her “Real Housewives of Beverly Hills” co-stars were not part of the festivities.

“Well, I did have an invitation to them because I had it on email and it was all written out for all of them, you know. And they’re not here,” Vanderpump, 58, told us. “I think it was probably because I forgot to press the send button.”

Fortunately for Vanderpump, longtime pal Camille Grammer offered her support, attending the bash with daughter Mason, 17, their rabbit and one of their friends.

“We’re actually filming ‘Housewives’ here tonight, funny enough,” Vanderpump said. “[Cameramen are] here tonight. That’s why Camille and I — we’ve been friends for years, she came to join me.”

Grammer, 50, who also appears on “Real Housewives,” said she is here for Vanderpump.

“She’s been awesome with me this year,” Grammer told us at the event. “We both have lost in our life. I lost my assistant who was with me for over 22 years and it’s like family to me. She, unfortunately, lost her brother. So she helped me, coach me through the grieving process.”

Grammer has also endured a rough few months, as her Malibu home was destroyed by the California wildfires last fall.

“We’d have long conversations about it and she was the first one to contact me about my house because Robert, her friend who’s a reporter, was on the ground there reporting my house,” Grammer explained.

“So we were on the phone discussing grieving and then I get a call and a text, ‘Camille. Your house,'” she continued. “We were in San Diego. We were evacuated the day before. And it was devastating to lose my assistant, then my house and Lisa, she was very supportive and she had a lot of good things to say to help me through that time.”