When a situation becomes unsettling, unnerving, frightening, or threatening one might colloquially say that things are "getting hairy". An entry on urbandictionary.com says it's used in awkward or uncomfortable situations. Perhaps it can be said of anything frightening, overwhelming, awkward, or difficult somehow.
Lairy is more often used to refer to people when they are acting aggressively.
"Now, now, calm down, don't get all lairy".
I'm British and these both seem like British colloquialisms to me. I've only ever heard 'lairy' used by Brits.