Mark Harris used to go into schools to give career talks, and ask the pupils to guess what job he did. "I'd get security guard, policeman, Fat Controller, butcher ..."
I start laughing, because he really does look like a butcher. He's got that bald head, scruffy grey beard and big belly you immediately associate with someone elbow-deep in offal and sausages.
"Don't go there," he says, laughing too. "Especially in the context of women giving birth."
Harris is a midwife - and the children never guessed. But that's hardly surprising. Because, apart from the fact that he looks more like a bouncer than an archetypal nurse, male midwives remain a surprisingly rare breed. Of the 42,000 midwives in the UK, there are only 122 men, according to the Nursing and Midwifery Council.
When Harris, 51, qualified in 1994, he was one of just 61 men who were registered. He admits that people endlessly used to raise their eyebrows.
Pregnant women, however, were mostly open to the idea. But that was because he insisted a female colleague always warned a patient that she was due to be looked after by a man, and ask if they were okay with the idea.
"Only if a woman said 'yes' would I go into the room. I would talk to her and make a connection. And I would insist at the end of that chat that they told me if they were uncomfortable. I promised them that I would not be offended."
He reckons he's delivered more than 500 babies. How many people said no to him being their midwife? "I can count it on one hand."
Having "at least" three babies named after him must be proof that many women find Harris a welcome presence in the birthing room. I can believe it. Beneath his Vin Diesel exterior, he clearly has a huge heart and during our chat manages to both laugh and cry frequently.
After 20 years of practising, he has written a book, Men, Love & Birth. It is aimed at a group often overlooked in the birth process: fathers-to-be. He wrote it after running a course called "Birthing for Blokes" in his home town of Leicester. "If I'm honest, a lot of people come along because their partners have sent them." Men, he says, too often feel like a spare part - even those who have read the books and can tell the difference between a uterus and a urethra.
"It doesn't just feel powerless, it feels emasculating. At the moment when the one they love is having stuff done to her, they feel completely unable to handle it. Not only that, they have professionals around her saying, 'Can you move away?', 'Can you sit down?', 'We'll be back for you' after they've rushed her off to theatre."
He says men - usually because they are scared and anxious - often make inappropriate jokes, absorb themselves in the sport on the hospital TV or just become "disengaged". In my case, midway through the labour of our fourth child, I left my wife in the hospital's birthing pool to fill up the parking meter, thinking (probably correctly) that was the most useful job I could do. At least I didn't head-butt the paediatrician - the worst example, Harris says, of an over-anxious father he's witnessed. "It was horrible. They had to call the police."
His book tells men how they can help their partners in the run-up, during and after birth. It mostly boils down to two ideas: don't panic and help her relax.
Along the way there are tips and some easily digestible science about increasing your wife or girlfriend's oxytocin levels. This involves giving her massages and doing more housework. There's also a fair amount of "New Age toss" (his words) about the "hormones of love".
Possibly his clearest advice is to avoid One Born Every Minute, the popular documentary series filmed on the birthing ward of a hospital. He objects to how the editing process turns so many of the births into dramas. "For the first time in many, many years, tokophobia levels [the fear of giving birth] are on the rise. This is not a general anxiety, this is a phobic response. There is definitely a link with the reality-type shows such as One Born Every Minute."
He is a fan of Call the Midwife, the BBC period drama, though, because it celebrates an era when home birthing was the norm - something he thinks more couples should consider.
Of course, most men only started attending the birth of their own children from the 1970s onwards, and there are still some who don't like the idea. And Harris thinks it is better for a man not to be in the room if he is unwilling.
But he is firmly of the view that a male midwife can be as empathetic as a female one.
"I remember being at a birth once, and the woman was 16. She had her mum in the room, her dad - bizarrely - in the room, her partner in the room, her sister in the room. She's in a rocking chair, and she's rocking back and forth and the baby's head is starting to crown. That's a wonderful moment. And she was crying, and granddad was crying, and I was crying. And in that moment I am just alive. It ignites your humanity."
He starts to cry again at the memory.
Harris has six children and eight grandchildren, but says he couldn't have been a midwife for his own brood. "I am as calm and focused and as present at a birth as it is possible to imagine. But for my own daughter? No! Being father, grandfather and midwife all at the same time - what a challenge!"
'Men, Love & Birth' by Mark Harris is published by Pinter and Martin.
The Telegraph, London