It's their safe haven and if we so much as look in its direction we're told we're invading their space.
We're lucky we're allowed on the same floor as it sometimes.
Here are just 10 reasons your teen's bedroom is, and always will be, out of bounds.
And frankly, we're grateful for it.
1. It's where your teen daughter perfects her flirty, pouting face in the mirror.
Do you really need to see that?
2. It's where your teen son applies hair gel for 37 minutes before emerging looking exactly the same.
Even he knows that's weird.
3. It's where your teen daughter sulks and cries over how much she hates you.
You get that in the kitchen and living room - do you really need to see it in every room in the house?
4. It's where your teen son balls up his football socks until the smell forces him to sleep in the TV room.
Yeah, that's his problem.
5. It's where your teen daughter discusses how much she loves that gormless- looking 20-year-old from the corner shop.
You just about stomached hearing that the first time.
6. It's where your teen son flexes in front of the mirror while simultaneously eating his leftover school lunch.
Catching his dad at it was enough frankly.
7. It's where your teen daughter listens to One Direction.
8. It's where your teen son hides his failed Maths papers.
Ignorance is bliss sometimes.
9. It's where your teen daughter keeps her hair extensions, fake nails, fakes eyelashes and fake tan.
It's like she's got the making of another human in there.
!0. It's where your teen son murders classic Rolling Stones songs.