We've all heard of shotgun, but shotgunning in your own home? I must admit that's a new one for me.

A stepmother has now caused a sensation online after describing an encounter with her stepdaughter in which the latter dared to sit in 'her' seat.

In a post titled "Is gesturing for someone to move rude?", the comments section exploded on the popular parent site Mumsnet.

The user explained her predicament: "Just that really, I thought it was no big deal but is it really rude?

"I had my son and DIL (daughter-in-law) over. My husband and I have assigned seats on the couch where we always sit. DIL always sees me sitting in that exact spot.

"I came back from the kitchen to the living room and she was sitting there. I gestured for her to move with my hands and she said something along the lines of "just ask me to move please, don't gesture to me" I politely reminded her that she was a guest in my house and my sons thankfully took my defence.

"My husband thinks she was right. So I was wondering, was it really rude? To me it was no big deal at all and she looked like she just wanted an excuse to start an argument."

Unsurprisingly, the comments didn't take to the mother's argument.

"You sound like one of the mothers in law who receive so many complaints on mumsnet. Madness," one user said.

Another replied: "I have a seat I usually sit in out of habit but I wouldn’t ask someone to move from it and I definitely would(n't) wave my hand at them and expect them to jump up."

Someone else commented: "You are so rude and your sons should have not defended you.

"I used to have a family member who was so neurotic and had assigned seating and god forbid anyone who sat there."

Why do people have to sit in an assigned seat?

Well, it’s environmental psychology.

This behaviour is an expression of “territoriality.” Territoriality is a spatial organising mechanism that expresses itself in surprising ways.

“Usually territoriality is thought of in terms of aggression and defence, such as when nations or gangs fight, but its most common purpose is to keep the peace,” says University of Victoria psychology professor Robert Gifford.

“Most of the time most people claim a space and others tacitly agree to it,” he added.

But anyway, back to the stepmother.

"Assigned seating, does that cost extra? Do you work for Ryanair? And yes, you were rude. Your ds is probably afraid to tell you," another said.

Someone else replied: "She was fair enough to ask you to not gesture. You started being very petty with your response reminding her she’s a guest in your house and what not. Shameful your son didn’t side with his partner tbh - if I was her I wouldn’t be a DIL much longer!"