The couple was fighting. It was obvious to anyone who looked. Her shoulders were pulled back in her short-sleeved black shirt and the look on her face could only be described as tense. It was a restaurant buyout and people were milling around, as people at parties often do. Does anyone else feel uncomfortable standing around while trying to balance both a plate and a glass? I know I do. But just because one is uncomfortable doesn’t mean that one is unobservant.

I wasn’t aware of when the fight started, but I first noticed it over by the bar. The man in the couple was talking to a different woman in black leggings, high heels and a headband.

The woman in the leggings touched his arm several times and she laughed at whatever it was that he whispered in her ear. And I mean she laughed and laughed. And touched and touched.

When the other woman approached the two of them, she stopped laughing. And she stopped touching. He, for his part, stopped whispering.

Some sort of discussion then ensued. And even from a distance, it was clear that the first woman wasn’t happy. The man shrugged his shoulders in that manner that certainly says “What?” while the woman in the headband stormed off.

Restaurant buyouts are an odd animal. Someone’s definitely footing the bill. But it’s often hard to tell who that is: for both the staff and the people attending. There are two resilient truths about restaurant buyouts:

• The first thing ordered from the bar when it opens will be something that the bar doesn’t have.

• The last two people at the bar at the end of the night will be two people the host doesn’t know, and those two will be trying to order the most expensive thing that they can get their hands on.

“Is it OK if I get a bottle of wine?” asked someone of one of the servers.

“Sure,” replied the now-identified host.

A $300 bottle of wine was ordered, something which was sure to annoy that host later, as the wines selected for this soiree topped out at $65. But that’s the nature of parties with 100 of your “closest” friends — and their plus-ones.

I once cautioned a couple who wanted to serve their guests martinis and Manhattans before their wedding ceremony.

“Not a good idea,” I had said.

“Why not?” they had asked.

Because those drinks are essentially doubles. (Martinis and Manhattans contain 2 ½ to 3 ounces of booze each.) And if those drinks are made with gin and whiskey, the average proofs on those two spirits hover around 90 (vodka and tequila are 80 proof). So, a couple of high-proof double drinks are going to get your guests more than a little tipsy — neither great from a liability standpoint nor from the standpoint of decorum.

The two women involved in the fight passed each other holding drinks. And for all their studiously avoided gazes, and the abundance of room between them, they bumped shoulders, spilling their drinks.

Outside of the noise made from the broken glass, the yelling and finger-pointing made more. The whispering man made his way over to the two women. He grabbed the one in the short sleeves, and who can only be surmised as the manager grabbed the other one.

The woman in the short sleeves slapped the man holding her, once fairly lightly. And then again, just a bit harder.

He still had that look of “What?” on his face. The threesome finally became disentangled and were sent off in different directions.

The bussers were busily cleaning up the mess, and soon it was as if nothing had happened.

Eventually, those two women came back together, as people in conflict so often do. They just can’t help themselves, which is why bars often ask people involved in conflicts to leave, even if the conflict was relatively minor. The first conflict is never the last one.

Those two women again bumped into each other, this time carrying plates. It was as passive aggressive as it gets.

“Darn it!” said the manager, getting involved again. “Tara and Louise, if you two can’t work together, I’m sending you both home.”

The two women stood there looking their feet while the party guests milled around them.

“And that goes for you, too, Ramon,” added the manager, pointing at the man.

Leaving me with these thoughts:

• Romance-related fights are always uncomfortable to witness in the restaurant business, whether the fight stems from the service side or the customer side.

• No-host bars are always the best way to go in a restaurant buyout, both from a liability standpoint and a financial one.

• There’s no such thing as a love triangle. There’s simply a person in the middle who likes attention.

• Workplace romances are never secret, no matter what the participants think.

Jeff Burkhart is the author of “Twenty Years Behind Bars: The Spirited Adventures of a Real Bartender, Vol. I and II,” the host of the Barfly Podcast on iTunes (as seen in the NY Times) and an award-winning bartender at a local restaurant. Follow him at jeffburkhart.net and contact him at jeffbarflyIJ@outlook.com