Heather Locklear?!?!?!? How Does She Fit Into the Denise Richards-Lisa Rinna Feud?

Lisa Rinna went there on Wednesday night.

On the season finale of The Real Housewives of Beverly Hills, Rinna and Denise Richards went at it, making it clearer than ever before that their friendship is over.

Long, long, long over.

locklear/richards

The actresses clashed over Richards' constant insistence that she was never close with Brandi Glanville, despite this reality star alleging that not only were the pair close...

... they actually slept together last year!

At one point, Rinna pulled out text messages allegedly sent from Richards to Glanville that proved the two were at least good friends.

"I don't like bullshit. Let's go through it!" Rinna screamed, holding up these text messages for the camera.

Lisa Rinna with Texts

Aside from a back-and-forth over the Glanville allegations, though, Rinna and Richards also argued over... Heather Locklear?!?

Yes.

"I go back to when she was friends with Heather Locklear," Rinna said late in the reunion special, citing the veteran actress and prompting Richards to cut her off.

"I actually wasn't, Lisa, and you know that. To bring that up, really?" replied Denise, in shock. "She was friends with my ex-husband. Now you're grasping at straws ... really?"

Denise Richards Cries Hard

Andy Cohen asked the women what Locklear had to do with anything here, to which Rinna told him to "Google it."

Welp, guess what:

We did just that!

And here's what we found...

Denise Richards Holds Back

In 2006, the long-time Melrose Place filed for divorce from rocker Richie Sambora following 11 years of marriage and one child together, daughter Ava Sambora, 22.

Shortly after Locklear and Sambora's split, the Bon Jovi guitarist started dating Denise, who was going through her own divorce at the time from ex-husband Charlie Sheen.

This quartet had been friendly for years because Locklear co-starred with Sheen on the ABC sitcom Spin City from 1996 through 2002.

“My mother has cancer and Richie’s father has cancer,” Denise explained to People Magazine in 2007 of how they connected.

“It’s hard. Thank God Richie and I have each other not only to go through divorce, but to go through both our parents being ill.”

Lisa Rinna Goes Off

There was speculation at the time, however, that Richards had slept with Sambora, or at least acted in some inappropriate manner with him, while he was married to her pal, Locklear.

Richards vehemently denied this was the case.

Speaking out for the first time about her relationship with Richie, Denise told Entertainment Tonight in June 2006:

“The thing with Heather, that’s been hard. You can’t help who you fall for and that friendship, unfortunately, was done and wasn’t salvageable.”

Denise Richards in Defense Mode

Richards admitted back then that people viewed her as a "crappy friend" for getting together with Sambora, but also insisted there was no infidelity on either siide.

“We didn’t meddle in marriages and anything like that," she said well over a decade ago.

Some wounds do not heal over time, though, and Glanville claimed to Andy Cohen this summer that she heard from Locklear amid her feud with Denise.

Denise Richards for Bravo

"Heather just reached out to me and said 'thank you' with a bunch of hearts and prayer [emojis]," Brandi said during an appearance on Watch What Happens Live.

"It just made me feel like I was probably bringing this side of Denise out for everyone to see, and I wrote back, 'Of course, the truth always comes out,' and she wrote a bunch more hearts.

"And then I said, 'Hey, you should be on Watch What Happens Live with me,' and she said, 'I've already had a cease and desist from Denise, so I'm not going to do it.'"

We're yet to figure out what the heck Glanville was talking about here -- there's no record of a cease and desist being sent from Richards to Locklear.

Denise Richards: Peeved in Pink

But there is now a record of Richards losing yet another friend.

"You’re a bad friend, Lisa," she told Rinna on the Season 10 finale.

"You are," said Rinna in return, to which Denise asserted, "I am not."

The Hollywood Gossip has been trying to contact Locklear to hear her side of the story. No such luck yet, however.