In recent weeks, Chrissy Teigen, Tyra Banks and women on Facebook have made it clear that you should never ask a woman when she plans to have children.
The reason being is that you never know what that woman is going through personally. She may not want kids, or she may be experiencing fertility problems. Either way, it's none of your business.
The debate around this nosey enquiry made me think about another question that, in my opinion, you should never ask another person:
"How do you stay so skinny?"
This question - along with its bitchier sister "why are you so skinny?" - has followed me around since childhood.
When I was around 10 years old, I went to the doctors about a cough. The GP raised my t-shirt to listen to my chest, then asked my mum to leave the room.
"Are you getting enough food at home?" he asked.
I assured him that yes, I ate a lot at home and at lunchtime, too. I told him that I was on my junior school netball team and went to dance class three times a week, so that was probably why I was a bit small. I hated sitting still but I loved spaghetti bolognese. He seemed satisfied with my answer and my mum was called back in.
I don't blame the GP for enquiring about my weight and wellbeing - in fact I'm glad he did, because the consequences if I had turned out to be a neglected child and he had ignored my protruding ribs would have been far more severe. Still, this small exchange was the first time I truly realised the extent of my childhood skinniness.
From then on I stopped finding it amusing when friend's parents said things like "you get skinnier every time I see you", "if you turned sideways you'd disappear" and "have more cake, you need fattening up". I knew these remarks weren't made in malice, but I still found them insulting.
In secondary school, it seemed the question "why are you so skinny?" was suddenly okay to ask. Teenage girls, not known for their subtly, tended to approach it in the form of: "Oh my God, are you anorexic or something? Like seriously though, are you?"
God knows how I maintained a healthy relationship with food while feeling like I had to justify the contents of my lunchbox to those around me.
But it was in sixth form that the question "why are you so skinny?" turned into "how do you stay so skinny?".
I moved schools and performed as Sandy in the sixth form production of Grease, skintight catsuit and all (as you do).
"Rachel, who knew you had such a voice. And such a figure!" a teacher of mine said in front of a full class the next day.
"Really I don't know how you stay so slim...."
She tailed off and waited. A class full of 18-year-old girls also waited. The expectant look on their faces made it clear they weren't laughing at me or calling me "too skinny". They were looking for diet tips.
I laughed it off, saying something along the lines of: "Oh I eat a lot really, it's probably all that dancing that I do."
And that was the first of many, many, many times I have shut down the question "how do you stay so skinny?"
I've been asked it by strangers in shopping changing rooms, when I've been sat by the pool on holiday and even while I was enjoying myself at a buffet. I've also been asked it at work.
I wouldn't dream of walking up to an overweight person and demanding to know what they had for dinner last night, but this has genuinely happened to me. More than once.
It doesn't upset me. I've learned to accept my straight up straight down figure. Yes, I'd quite like to have bigger boobs, but only in the same way I'd like to have a mansion with a tennis court. My mum is skinny. My nan is really skinny. Inevitably, I'm always going to be a bit on the skinny side.
"What's the problem then?" I hear you ask. "It's a compliment."
Well, as Chrissy Teigen said in regards to the question "when are you going to have a baby?", someday you're going to ask the wrong girl.
You're going to ask someone who is really struggling - perhaps with low self-esteem, an eating disorder, or a health issue that leads to weight loss - about something that is actually very personal.
By pointing out that they look "different", you're not going to make their body image struggles any easier, even if you think you're paying them a compliment.
If you're really looking for diet tips, go and read a healthy eating blog, there's enough of them out there.
But stop asking other women (including me) how they stay so skinny - it could do more damage than you think.