A very important theory about why Nicole and Keith love a red carpet PDA.

Close your eyes and write a headline about a sparkly, twinkly A-list event. 

The Met Gala. The Oscars. The Golden Globes. The Grammys. 

Here, I'll help. 

Nicole Kidman and Keith Urban Pack On The PDA On [INSERT EVENT HERE] Red Carpet. 

Yes, tonight the sun will set, tomorrow it will rise and if there is a red carpet in the neighbourhood, our Nicole will be on it wearing quite the dress and open-mouth kissing her handsome husband. 

Why? 

Look, I know I have better things to do with my time than answer that question. I know you do, too. But the news cycle is dark, bad things are happening, and if the first Tuesday in May isn't a time to celebrate beautiful people in love, then I just don't know what we're doing here any more.

Watch: Rami Malek respond to an awkward Nicole Kidman moment. Post continues after video.

And so, behold my very quick and deeply serious, four-pronged theory about why Nic and Keith PDA. All. The. Time.

1. Because Nic is hot, dammit. 

Early in Nicole Kidman's career, she was a tall, skinny redhead in a world of celebratedly-sexualised bombshells: Kim Basinger, Angelina Jolie, Halle Berry... And the Tom Cruise-era headlines were cruel. She was labelled an ice queen. There was the vile hiss of rumours about her motivations, her sexuality, her fertility. It was bulls**t. It was the 90s. 

The post-Tom version of Nicole was a free f**king spirit, who whooped outside the divorce lawyers' office (hello, infamous pap photo), who made risky career choices (hello, fake nose in The Hours), who dated hot musicians, (hello, Lenny Kravitz).

You can project all the ice-queen bulls**t you want onto her, but PDA Nic says, but she's sexy, self-realised woman who loves love. Don't you forget it.  

2. Because being a grown-up doesn't make you sexless. 

Nicole Kidman is 55 years old. I know, I know, not your version of 55 years-old – or mine – but a Hollywood imagining of what mid-50s looks like. 

She's at the absolute top of her game, but she's swimming in a youth-themed ocean, battling the tides of ageism and competing for covers with Lily Rose Depp, whose dad she knew before he was a punchline. 

Nicole wants – no, needs – you to know that she might be a proper grown-up now, but she's never been better at her job, never looked better, and she's not about go quietly into the night, with her Wordle and her gardening gloves. 

3. Because they're parents and this is A-list date night. 

Come on. They've got tweens. 

With their schedules, they don't get out much. The Met Gala red carpet is their version of a local pub dinner and a tipsy smooch before someone has to take the babysitter home. 

Mum and Dad are busy, people. 

4. They like each other. A lot. 

Nic met Keith in 2005. That's the best part of 20 years. If they're still pashing in public after almost two decades, they're not like every other long-term couple you know. 

Nicole doesn't cringe when Keith chews his food. Keith doesn't roll his eyes when Nicole reminds him to wring out the J-cloth before he leaves it in the sink. 

Nup, Nic and Keith are long-term lovers who are not ready to sign up for separate bedrooms, bum-sagging PJs and the post-sex life. Are you paying attention?

Thank you for coming to my Met Gala-inspired Ted Talk. 

See you next time we all need cheering up. 

Now treat yourself to a listen of the latest episode of The Spill, covering every controversy from this year's Met Gala:

Image: Getty + Mamamia. 

Calling all Beauty Lovers! Take this short survey now to go in the running to win a $50 gift voucher!