Sour Nose
When you go underwater and the water goes in your nose causing the sour sort of sting, mostly happens when upside-down.
The boy almost got the keys from the bottom of the lake but he got Sour Nose and had to come back up.
Sour nose
When you're about to cry and you're trying to hold your tears in. That tingling feeling in your nose feels a bit sour.
"Are you ok?"
"Yea, hol' up. I have a sour nose."
"Yea, hol' up. I have a sour nose."