Dear CF: For all you know, you might have stepped into some dog doo-doo and your colleague was merely trying to scout out the source of the odour. At least that's the story I think you should stick with. "Hey, Bernard; I meant to ask you if my shoes were bothering you the other night -- I think I tracked in some dog poop -- sorry." It lets him off the hook but also sends the message that he's been seen. Yes, he may have a foot fetish -- the fragrance of footwear is a turn-on for some. If it makes you feel better, put yours in a bag instead of letting them hang in the hallway. Going up the corporate ladder is a bit heavy; you have only vague suspicions at this point.