'RHOBH' Reunion Tea Time: Lisa Rinna Explodes on Lisa Vanderpump Over Instagram Posts -- 'Who Gives a F-cking Sh-t?'

Dorit also brought up Kyle's "involvement" in PantyGate again, which Erika Girardi quickly shot down, saying she knew Kyle was innocent. Then Teddi Mellencamp Arroyave's never-ending beef with Erika came up, which Erika also shot down -- except she did so not so nicely. Basically, absolutely nothing new was brought to the table, and nothing was resolved.

HOWEVER, there was one new feud that ignited Tuesday night, and it was between Lisa Vanderpump and Lisa Rinna, who's had a rather tame season compared to last year's. (We'd be lying if we said we didn't miss Coke Den Lisa.)

Over the holidays, Rinna decided to watch some of the earlier seasons of "RHOBH." She posted screenshots of Vanderpump on her Instagram story, captioning the images with her reactions.

Some of the captions Rinna posted included, "Oh. These tired old quips started in Season 1?! Oh!" and "Who the f-ck is that?" and "Wait, who's that?!" and "Seriously, is that Vanderpump?"

One of Rinna's messages was in regard to Cedric -- Lisa and Ken Todd's very close friend, who they once treated like a son. They brought him over from England, fed him, housed him and took care of him for years. Cedric eventually screwed them over, which hurt Lisa deeply. Their relationship and its demise were documented on "RHOBH."

"That's really nasty of her to say that because he caused our family a lot of grief," Vanderpump said about Rinna's Cedric comment.

Rinna claimed she didn't know what Cedric caused Vanderpump's family, because she "didn't watch the whole thing."

"You really had a go at Lisa Vanderpump, though," Kyle chimed in. Vanderpump added that she never saw the stories herself but that Kyle told her Rinna had "said some really nasty things."

"Lisa, it was jibs and jabs," Rinna said. "We had just come out on the show, and you had jabbed me so hard. You have to have a sense of humor about this stuff."

"I didn't see it sweetie," Vanderpump replied.

"Well, then, who cares?" Rinna shot back. "What're we talking about?"

Rinna then said she thought Vanderpump would "laugh at it," but Kyle seemed to think otherwise.

"Unless you saw it, you should just shut up," Rinna eventually fired at Vanderpump. "Are you kidding me? My Instagram stories that go away in 24 hours? Who gives a f-cking shit?!"

Part 2 of "The Real Housewives of Beverly Hills" reunion airs May 1 at 9 p.m. on Bravo.