Lisa Vanderpump on Kyle Richards feud: 'It's been very sad'

April 10 (UPI) -- Lisa Vanderpump says her feud with Kyle Richards has been a "very sad" experience.

The 58-year-old television personality discussed her falling out with Richards, her longtime friend and Real Housewives of Beverly Hills co-star, during Tuesday's episode of Watch What Happens Live.

"It's been very sad," she told host Andy Cohen. "I would never accuse somebody of doing anything unless I had proof."

Vanderpump had sworn to Richards on her children's lives she did not leak a story about Dorit Kemsley, who adopted a dog from Vanderpump's organization that ended up back at the center after being dropped off at a shelter.

"When you swear on your children's lives -- to me, that is sacrilege -- I'm not going to tempt fate of the two people, and Giggy, that I love more than anything else in the world," Vanderpump told Cohen.

Vanderpump and Richards had a blowout fight last week on Real Housewives of Beverly Hills after Richards accused Vanderpump of spreading the story about Kemsley. Vanderpump told Cohen she does miss her friendship with Richards.

"Well, I think we had a lot of fun together," she said.

Cohen asked Vanderpump whether she respects Richards for "playing the middle" amid the drama.

"I think Kyle always does that," Vanderpump said. "When you're a good friend, I think you stand up for them."

"Of course I miss that friendship," she added. "But maybe it wasn't such a good friendship after all's said and done."

Vanderpump told Entertainment Tonight last week a reconciliation with Richards and their co-stars is unlikely. She said she stopped filming halfway through Season 9 because of the conflict.