A chum of mine learned this the hard way recently when he took a day off, innocuously claiming he was a bit under the weather. His colleagues sent him the obligatory texts enquiring after his health while blaming their boss for overworking him.
As they tut-tutted their way down the street for lunch, whom should they run into but our indisposed friend, looking dapper in his most expensive suit.
Feeling cornered and unable to come up with anything intelligent, he blurted out that he was there for a job interview. Sure enough, the news found its way back to the aforementioned boss in no time.
Luckily for my friend, he got the new job and could walk away from the fuss unscathed, although not without shooting the sympathisers a stink eye that could make a dead flower wilt.