Real Housewives Premiere Party: Brandi Glanville & Kyle Richards "Very Tight," Lisa Vanderpump Kept to Herself

Get the scoop on all the drama from last night's Beverly Hills bash

At last night's Real Housewives of Beverly Hills season-four premiere party, Lisa Vanderpump was at the center of the drama.

While the rest of her RHOBH castmates mixed and mingled during the bash, Lisa kept to herself and stayed mostly on the other side of the room from the other ladies, who we hear aren't talking to Lisa currently.

"There's tension between her and the other women right now, so she wasn't doing a lot of mingling," a source tells E! News. While the source says "she kept to herself," Lisa's hubby Ken Todd made the rounds with their dog Giggy in his arms.

While Lisa avoided the other women, Brandi Glanville and Kim and Kyle Richards took over a corner with their respective friends and family members. "The three of them were very tight," an onlooker says. "Out of everyone in the cast, they seemed to be having the most fun. They were definitely there to party."

While there's been tension in the past between Kyle and Kim, "last night they had a ball together," the guest continues. "They were dancing and singing the lyrics to ‘Single Ladies.'"

And for Brandi, the night was about more than just the show. "She brought Drew Carter and they spent a good portion of the night dancing together," the source says of Brandi and her beau, adding, "They're on and off. They have fun, but it's not that serious." Two of the last to leave the party were the new castmembers Carlton Gebbia and Joyce Giraud.

All the drama surrounding Lisa and the other gals began when they all went to Puerto Rico for a trip and butted heads. After the beef, Lisa was no longer getting along with any of the other RHOBH ladies.