I'm beginning to think that Mr P has a condition, bin allergy.
He's a good man in so many ways, (his bath robe has "Best Chap" embroidered on it) but although he brings me a cup of tea most mornings, I often find the teabag on the edge of the sink. He also has a bit of a thing about milk. I buy a new carton, the old one may still have enough in it for a few cups of tea/coffee, but no, the minute he sees a new carton, that's the one he has to use. Depending on the supplier, there is either a plastic strip thing that you pull off from the rim of the cap, or a pull back white thing under the cap. Whichever, it is always left on the work surface. 
I also refuse to gather his washing. We have a perfectly functional wicker basket in the bedroom, but he seems to prefer the floor, then wonders why his clothes seem to be covered in cat hair 
When I am preparing to do a load, I place a plastic basket on the landing and ask him to put in whatever he wants washed. The number of odd socks that I find at the end of my laundry time is pretty impressive!
I have a secret place that I keep them in until they can be reunited with their matches! If I didn't, I'm sure he would adopt a "near enough" attitude.