Just when you thought the Lisa Vanderpump and Kyle Richards feud had been packed away in the Bravo archives, somewhere between a few questionable hairstyles and a mountain of broken friendships, Lisa has reminded us that some grudges come with an exceptionally long shelf life.

Lisa Vanderpump has opened restaurants, bars, a villa and now a Las Vegas hotel with its own casino.

The one door she has never quite managed to reopen? The one marked Kyle.

And apparently, simply working for Kyle Richards is still enough to land you in trouble.

THE PARTY PLANNER — Kevin Lee Gets Caught in the Middle.

On the October 20 premiere of Vanderpump Rules: Lisa Las Vegas, Bravo's special following the opening of the Vanderpump Hotel, Lisa confronted her longtime friend and party planner, Kevin Lee.

His offense? Working with Kyle Richards on her extravagant, $400,000 White Party at SoFi Stadium, the grand finale of Season 13 of The Real Housewives of Beverly Hills.

And apparently, that wasn't the end of it. Kevin also helped Kyle pull off another White Party for The Real Housewives Ultimate Girls Trip: Roaring 20th, celebrating the franchise's 20th anniversary.

One thing's for sure: Kevin knows how to throw a party. Unfortunately, he also knows how to land himself in the middle of a Housewives feud.

Let's appreciate the timing. Lisa is opening a 188-room hotel with a 40,000-square-foot casino, and she still found the time to settle a score over a couple of parties.

Priorities.

Kevin had planned events for Lisa for years, including Pandora's wedding. So when he went to work for Kyle, Lisa wasn't exactly sending congratulations and a bottle of rosé.

She felt betrayed.

Kevin explained that it was simply business. Lisa wasn't buying it. In her world, loyalty doesn't come with a convenient business exception.

In most industries, a supplier taking on a new client is called growth. In Beverly Hills, it's called a diplomatic incident.

Lisa asked Kevin how he would feel if she worked with someone who had seriously hurt him. A fair question, and also the kind with only one acceptable answer.

Kevin found it. He apologized, and the two embraced.

Crisis averted. Flowers ordered. Friendship restored.

For now.

Because if seven years of Puppygate have taught us anything, it's that Lisa Vanderpump doesn't forget. She forgives selectively, and she files everything.

Kevin may have gotten his hug, but somewhere in Lisa's impeccably organized memory, there's now a little note next to his name. Handwritten. Almost certainly in pink.

And if Kyle ever calls about another White Party, Kevin might want to let that one go to voicemail.

Kyle Richards, however, remains firmly on the other side of the garden gate.

THE CONFESSION — Lisa Misses Kyle. Just Not Enough to Call.

Here's where things get interesting.

Lisa admitted that she misses the friendship she once shared with Kyle.

Missing someone and wanting them back in your life, however, are apparently two very different things.

Which is understandable, considering how spectacularly that friendship imploded during Season 9, when Puppygate turned Beverly Hills into a canine courtroom drama.

Remember? A disagreement over Dorit Kemsley's adopted dog, Lucy Lucy Apple Juice, somehow became a full-scale investigation into loyalty, leaked stories and who was calling whom a liar.

Seven years later, we're still talking about it.

One small rescue dog managed to end one of the most famous friendships in Bravo history. Frankly, Lucy deserves an executive producer credit.

THE MATCHMAKER — Even Andy Cohen Wants Them Back Together.

Andy Cohen has made no secret of the fact that he'd love to see Kyle and Lisa reconcile.

During an October 19 appearance on TODAY, Andy said he loved their friendship, while acknowledging that a reunion doesn't look particularly likely.

And here's where things get even more ridiculous.

According to Andy Cohen, Lisa and Kyle occasionally run into each other at Beverly Hills restaurants, where they send bottles of champagne to each other's tables, complete with shady little notes.

Seven years of feuding, and they're still communicating through champagne and sarcasm.

Apparently, they can't stand each other, but they're perfectly happy to keep each other supplied with bubbly.

Only in Beverly Hills can a peace offering arrive with a side of shade.

Kyle, for her part, has previously acknowledged that Lisa has many wonderful qualities, while admitting their relationship left her with some painful memories.

Gracious. Measured. And not remotely an invitation to lunch.

Neither woman appears ready to wave the white flag. Although, given the circumstances, a white flag might be a little too close to a White Party.

THE DEBATE — Loyalty or a Very Long Grudge?

This is where fans will split right down the middle.

On one hand, Lisa has every right to decide whom she trusts. If she genuinely believes Kyle betrayed her, nobody can demand that she forgive and forget on a Bravo schedule.

On the other hand, Kevin Lee is a professional party planner. Planning parties is literally his job.

Should he really have to check Lisa's list of personal enemies before accepting a booking?

Given the last two decades of Bravo history, that list would need its own binder. Possibly its own party planner.

And let's be honest, Beverly Hills isn't exactly overflowing with people who haven't offended someone on reality TV. At this rate, Kevin might have to relocate to another state just to find an approved client.

Still, there's something almost comforting about the fact that, after all these years, the Vanderpump-Richards feud remains as reliable as ever.

Some friendships end quietly.

Others involve seven years of resentment, a dog named Lucy Lucy Apple Juice, a Las Vegas hotel, a party planner and Andy Cohen still hoping for a miracle.