"She's not pregnant," Gareth Williams insisted to the 999 call handler, his partner crying in pain in the background.
Nanoseconds later, the couple's thoroughly unexpected newborn son announced his arrival with a wail.
Rhiannon Oldham, aged 30, had been convinced she had simply put on a few pounds over Christmas, and said she had been suffering with heartburn.
"I just took a Rennie and got on with it," she said.
“I’d put on weight over Christmas too, but I just put it down to overindulging."
She never suspected she might be about to give birth.
- Listen to the audio from the call:
The couple got engaged on Valentine's Day.
Three days later, Rhiannon developed severe stomach pain, and 34-year-old Gareth dialled 999.
"On the Friday, Rhiannon had been complaining of stomach pain but we dismissed it, and just kept an eye on it,” he said.
“By the early hours of Saturday morning, she was in agony and I had to carry her from the bathroom to the bedroom, and that’s when I could see that something strange was happening."
During the audio of the call, released by Welsh Ambulance Services, he insisted a number of times that Rhiannon was not pregnant, and reported a "lump" coming out of her.
That turned out to be baby Phillip Alan's head.
“It was a huge shock because we had absolutely no idea that she was pregnant," he said.
"But we’re over the moon.”
“The last couple of weeks have been a blur. One minute we were planning for a wedding – now we’re planning for a nursery," Rhiannon added.
The couple, after a brief spell in hospital, have now been reunited with the call handler and the paramedics who helped them through the experience.
Paramedic Paul Ockenden and student paramedic Sian Todd were first to arrive at the couple’s home.
After first receiving the call, they thought they might be faced with a case of appendicitis.
“The initial call we had was to a female with abdo pain, and the next message we had was that a midwife was en route, which we thought was unusual," Paul said.
“When we got to the property, Gareth led us to the bedroom and there was Rhiannon on the bed cradling their newborn baby.
“It’s fair to say they were a little shell shocked, but we set about making the necessary checks and then Gareth cut the cord.”