A pair of identical twins in Australia who share a fiancé and live identical lives have decided to conceive babies at the same time.
Anna and Lucy DeCinque, 35, spend every minute of their day together including eating, showering, dressing, and sleeping.
But the twins' nine-year partner Ben Byrne, 40, will have quite a job on his hands to make the simultaneous conception work.
Anna told the New York Post: "When she goes to the toilet, I come with her; when she has a shower, I come with her.
"You name it and we do it.
"We're never apart - I don't think we'd function without each other."
The 35-year-old from Perth even claimed the pair experience separation anxiety when away from each other.
The world's most identical twins are so bound to each other they even measure their food to make sure their portions are the exact same amount.
In one YouTube video they can be seen measuring their temperatures together to check their menstrual cycles.
As a result of their lifestyle, the women's ovulation cycles have aligned to match each other.
Both their temperatures reached 36.8C.
Lucy said: "We learnt from the internet that when you temperature goes up, you're ovulating."
Both added: "'We're the three degrees up. We are ovulating, we are exactly the same!"
They called Ben into the room to share the news and, in an attempt to avoid sharing too much, the women are next seen with their legs up against the wall.
This technique is a common myth that is supposed to encourage successful fertilisation.
The twins have also opened up about the actual difficulty of getting pregnant.
They revealed the process was much harder than expected and even harder to align the pregnancies at the exact same time.
But compromising on the synchronisation of their conceptions is not an option for either of the Perth girls who even go to the loo together.
A new reality TV series entitled Extreme Sisters by American TLC is documenting the sisters' lives for the world.
Lucy told Confidential: "'We were ready to showcase our love story.
"We are the show to be quite honest, I don't think there's anyone more extreme than the two of us."
The programme already launched in the US depicts the lives of four other sets of siblings alongside Anna and Lucy.