We have all, at some point, watched a close friend vanish into the hurl-dorable vortex that is love. I know I have! And, of course, many of us have entered that vortex ourselves. One that may include (for instance) repairing one’s beloved’s only flaw — “You’ve never seen Buffy?!” — with an intensive marathon that also, necessarily, includes Angel. Then she/he is all, “You’ve never seen The Wire?!” and poof, you emerge months later into the sun, glassy-eyed, watching your back for vamps, and wondering where all your friends went.

Well, Buffy or no Buffy, the friend attrition that comes with love is definitely a thing, according to new research at Oxford University. In fact, they counted:

Oxford University researchers asked people about their inner core of friendships and how this number changed when romance entered the equation.

They found the core, which numbers about five people, dropped by two as a new lover came to dominate daily life.

“People who are in romantic relationships — instead of having the typical five [individuals] on average, they only have four in that circle,” explained Robin Dunbar, a professor of evolutionary anthropology at Oxford.

“And bearing in mind that one of those is the new person that’s come into your life, it means you’ve had to give up two others.”

But it doesn’t have to be this way, does it? On the one hand, you know, your friends don’t come on your honeymoon: even grudging single friends should allow their newly smitten compadres and compadrinas a grace period. It’s a thrilling, fizzy, heady time, and we need to give them that, just as we’d want them to “let” us have ours. On the other, folks, even if you find that special someone who “gives you everything” and “meets all your needs,” well, they don’t. They may be wonderful in every way — even a wonderful friend to you — but they’re not a full-on swap-in substitute for friend-friends. The bestest love relationships are those that enhance your lives and sense of connection to people and the world, and those in which you each have space and time to nurture your own, separate, friendships. So once you stop seeing those early-in-love stars, make sure you keep seeing your friends.

She slays us! Back in 2000, Marti Noxon — then supervising producer for Buffy and consulting producer for Angel — graced BreakupGirl.net with her presence, answering reader questions as part of our You & A Guest series, which also featured Kevin Bacon, Dan Savage, Martha Quinn, and even the boys of O-Town! (And significantly scooped other online pubs who wouldn’t do that for years. W00t!)

She’s been plenty bizzy since, but we’re extra-super-excited about her next gig. (In fact, she’s one of the few people we’d trust with something so tricky-yet-potentially-excellent.) Via Variety:

Diane Keaton is attached to star in a series project in development at HBO revolving around a feminist icon who launches a sex mag for women.

The untitled series is among the first projects to come from Grady Twins Prods., the production company formed earlier this year by TV vets Marti Noxon (“Buffy the Vampire Slayer”) and Dawn Parouse Olmstead (“Prison Break”).

The duo is also working with helmer Guillermo del Toro and author Chuck Hogan on a smallscreen adaptation of their book trilogy “The Strain.”

The Keaton project stems from Noxon and Parouse Olmstead’s interest in exploring the legacy of the feminist movement of the 1970s. Keaton was taking meetings for a TV series project, and she responded to Noxon and Parouse Olmstead’s vision for a show featuring a Gloria Steinem-type character who tries to reignite interest in femme-centered activism by launching a porn mag for women.

Noxon is writing the script and will exec produce along with Parouse Olmstead. After Keaton signed on, the lead character was tailored to the thesp’s background and experiences.

“We really value her experience and outlook on the world,” Noxon said. “She’s incredibly frank and honest as an actress and as a person, yet she’s also extremely private. We really want to capture that in the show.”

The “Strain” book trilogy is a bioterror thriller with fangs, telling the story of an outbreak in the U.S. of a virus that either kills those who are exposed to it or turns them into vampires. The first of the series came out in June. The plan is to shop the TV project, envisioned as an event series unfolding over three seasons, early next year after the second book is released.

Noxon and Parouse Olmstead have long been friends and occasional collaborators on such projects as the 2004-05 season Fox mystery drama “Point Pleasant.”

With help from their reps at WME, the two decided to go it alone as partners in Grady Twins after years of working for large production entities. (The Grady Twins moniker is a nod to the murdered twin girls who haunt the Overlook Hotel in “The Shining.”)

The two put up their own coin for office space in L.A.’s Larchmont Village and got busy setting up projects. “We both felt like it was a good time to strike out and not be committed to any one place,” Parouse Olmstead said. “The business models for network TV and cable TV are changing. We see this as a moment of opportunity for a company like this.”

The duo’s first series to go into production is “Gigantic,” a drama set for debut in January on the Viacom-owned cabler TEENick (the new name for the N as of September). Show examines the world of celebrity culture by focusing on high-school age children of fictional celebs.

As evidenced by Grady Twins’ initial batch of projects, Noxon and Parouse Olmstead aim to cast a wide net as producers. And they’re committed to live by the maxim that “we don’t want to be doing anything that we don’t have a passion for,” Noxon said.

Noxon’s recent primetime credits include “Private Practice,” “Grey’s Anatomy” and “Mad Men.” Separate from her Grady Twins labors, she’s set to make her directing debut on the indie feature “Box City” for Mockingbird Pictures.

May all karaoke bars observe a moment of silence for actor Andy Hallett, who played BG’s favorite character on Angel, which is saying a lot.

Of course, we prefer to think he’s gone back to Pylea to open a FANTASTIC club.

“They have no music there. It doesn’t exist. Do you know what that’s like? No lullabies, no love songs. All my life I thought I was crazy, that I had ghosts in my head or something… simply because I could hear music. Of course, I didn’t know it was music. All I knew was that it was something… beautiful and… and painful and right. And I was the only one who could hear it. Then I wound up here and heard Aretha for the first time.” — Lorne the Host