(right) under somebody's nose
if something bad happens under your nose, it happens very close to you but you do not notice it
under (someone's) nose
In plain view

[TahlilGaran] Dictionary of Contemporary English ▲

under nose
under (someone's) nose
if something bad happens under your nose, it happens very close to you but you do not notice it.
I'm amazed that it was going on right under his nose all that while and he didn't realize.

under (your) nose
obvious or not hidden.
Sorry it took me so long to see what was right under my nose.

Usage notes: also used in the plural form under your noses:
She has been right under our noses all this time!

Varies in the plural esp. as under the noses of sb, under their very noses, etc.--SL, 8/02

[TahlilGaran] English Idioms Dictionary ▲

under nose
easily found by someone, right in front of someone
I thought that I had lost my house keys but I found them right under my nose.

[TahlilGaran] English Idioms Dictionary ▲

under someone's nose
under (someone's) nose
if something bad happens under your nose, it happens very close to you but you do not notice it.
I'm amazed that it was going on right under his nose all that while and he didn't realize.

under (your) nose
obvious or not hidden.
Sorry it took me so long to see what was right under my nose.

Usage notes: also used in the plural form under your noses:
She has been right under our noses all this time!

Varies in the plural esp. as under the noses of sb, under their very noses, etc.--SL, 8/02

[TahlilGaran] English Idioms Dictionary ▲

under someone's nose
easily found by someone, right in front of someone
I thought that I had lost my house keys but I found them right under my nose.

[TahlilGaran] English Idioms Dictionary ▲

under one's nose
within sight of someone, easily seen or found
He found his driver's license right under his nose where he had left it.

[TahlilGaran] English Idioms Dictionary ▲

under one's nose
adv. phr., informal In sight of; in an easily seen or noticeable place.
The thief walked out of the museum with the painting, right under the nose of the guards.
When Jim gave up trying to find a pen, he saw three right under his nose on the desk.

[TahlilGaran] English Idioms Dictionary ▲