Sadly, we all know that Real Housewives of Beverly Hills stars Lisa Vanderpump and Brandi Glanville aren't as close as they used to be. And now Lisa is firing back at Brandi on Twitter for the first time.

We're all getting to see the gradual dissolution of the pair's friendship on Season 4, and it's been sad to watch. Recently, they have bickered about Brandi's drinking and whether Lisa was too pushy in trying to get Brandi to see a doctor about her broken hand.

Lisa says she hasn't written anything about Brandi on Twitter since their falling out last summer, but she finally tweeted at Brandi this week to address the drama.

Things started when Brandi tweeted on January 28, "Don't tell me you're my friend  show me."

Brandi hadn't mentioned Lisa's name in the tweet, but Lisa apparently assumed that it was directed at her. So Lisa replies to Brandi, "...I did."

And then Lisa made note of the fact that this is indeed the first time she's contributed to their drama on Twitter. "Yep, in six months of mud-slinging, that's my first response," Lisa writes. "Just two lil words.. 'I did.' And that's quite enough from me, so I will shut up." There you go.

How do you feel about Lisa and Brandi's Twitter exchange?

Source: Lisa on Twitter