Sentence:  He'd suddenly felt hot under the collar, having thought back to when Larry had so nearly been closer than anyone in finding out their secret; for it really had been far <WSD>too close for comfort</WSD> back there at the office, when he and Larry had met Anne outside the women's toilets, and she having been confronted by us, had suddenly become a quickly blushing, red-faced lady, almost as if she'd been seen in a state of undress, particularly when Larry had asked her what she'd been up to, meaning work that day! 
Meaning of the word marked with <WSD> tags:  Frightening because of almost resulting in injury or disaster.