Wedding photographers on the moment they know a marriage isn't going to last.

There’s only one person who pays more attention than you at your own wedding: the photographer.

And with this responsibility comes a gift. They swear they can tell immediately if a couple is going to last or not.

Wedding photographers of the internet came together to share their experiences of when they guessed it in a recent Reddit thread.

And for one of them? It came down to how they cut the cake. These are our favorites:

The ‘Kiss of Death’.

User Rorysparshott wrote, “My dad did wedding photography as a side project, and of the 27 couples he did over the course of four years, at least 20 have divorced. He considered rebranding as ‘Kiss of Death Photography Inc.’.”

It all comes down to intimacy.

SuccessiveApprox wrote, "We spend eight, 10, 12 or more hours in a day looking at the bride and groom through a frame that isolates them alone and together. We are looking specifically for moments of contact, of intimacy, of emotional connection. It pretty quickly becomes evident when those things are there, and when they are not." (Post continues after gallery.)

The sexual tension.

"Once there was more sexual tension between the groom and the best man than between the groom and the bride," SuccessiveApprox wrote.

Refusing to kiss.

One user named Colmes wrote, "My very first wedding was a couple who was getting married by the art museum in Philly. I had my friend whose been a wedding photographer for 10 years with me to show me the ropes. He poses a kissing shot of the couple, and when he asks them to kiss, the bride goes, 'Oh, no, no thank you.'"

The open relationship.

"When I first got started I assisted for a photographer who was a good looking man," Deweysizemore wrote.

"During the reception the bride told him they were going to have an open marriage and basically offered herself up to him, which he politely declined. It didn't work out."

Listen to the Mamamia Outloud team discuss wedding day regrets. (Post continues after audio.) 

Put your phone away.

DirectinLA has a brilliant horror story for us.

"One groom was on his phone while walking down the aisle," they wrote. "And he was in jeans. She wasn't the happiest."

The speeches.

User 2Dprinter, who runs a wedding photography company, says it all comes down to the speeches.

"What people who give speeches say about the person their friend/relative is marrying is a huge giveaway," they write.

"Do they feel like this person enriches their new spouse's life? Do they see them as an extension of their family or as a close friend? Are their anecdotes about how each person complements the other? Or are they simply 'happy for them'?"

How you cut the cake.

Now this is the strange one. 2Dprinter believes how a couple cut the cake is an important one to watch for.

"Sweetly feeding one another? Good sign. A playful smear of icing on the nose? No problem. But every once in a while someone will retaliate. Bad sign. I think it's indicative of the sort of contempt which will doom the relationship. Even if you don't want that fondant on your face, you need to be able to laugh it off and have a good time."