Lisa Vanderpump brings up the rumors of Mauricio Umansky cheating on Kyle Richards while she's at Kyle's house on last night's Season 4 premiere of Real Housewives of Beverly Hills. Now, Lisa is explaining why she did.

"While I am [at Kyle's place], Kyle brings up the fact that there have been stories created about her being pregnant," Lisa writes in her Bravo blog. "I also mentioned that I had seen the articles about Mauricio cheating. I would prefer face-to-face to acknowledge them, and then in the same breath, ridicule the constant nonsense that is often in these tabloids."

"The previous week, I had appeared on the very same magazine cover stating that they had discovered a sex tape!!!" Lisa adds. "As if!!! The only way I have of dealing with and enduring these hurtful, slanderous headlines is to give them as much credence as they deserve  zero."

Lisa points out that she had already publicly dismissed the rumors of Mauricio cheating. "I had been at an event a couple of days prior and publicly denounced the validity of these rumors regarding Mauricio on the red carpet," Lisa writes. "I was quoted using the terminology 'utter bullst.'"

It sounds like Lisa now regrets defending Yolanda Foster to Kyle. "I was adamant that Yolanda would never say derogatory things about me," she says. "Hindsight is twenty-twenty. I was warned and chose to ignore it, this is how the story begins..." Yikes. Indeed, Yolanda and Lisa are now on the outs.

Lisa also says she appreciates new cast member Carlton Gebbia taking issue with Kyle talking about Lisa's alleged nude scene. "If Kyle wanted to poke fun and draw attention to something that some might find embarrassing, I have no problem with it whatsoever, but I liked the fact that this quirky Brit was voicing an opinion," Lisa says of Carlton.

So it's the first week, and already we have major tension brewing. How much worse will Lisa and Kyle's friendship get, and at what point will Lisa and Yolanda have their falling out? We can't wait to find out.

Source: Lisa's Bravo blog