Make a list of your favorite pairings and explain who would pick up the socks and why.
Here’s the HP edition. I’ve got a West Wing and possibly DW/Torchwood one cooking.
Remus/Sirius: As boys at Hogwarts, neither really thought about who picked up their dirty socks or why. They’d be shed after dinner, or Quidditch practice or a particularly ill-fated Herbology class and would be gone by morning, replaced by a pile of freshly laundered ones in their trunks. That was until that week in Second Year when the house elves called a general strike on cleaning their dormitory after James charmed their laundry to spray Madam Scriven’s Semi-Permanent Seven-Coloured, Seven-Scented Ink over anyone who touched an offending item.
It was during that week they discovered: a) Sirius was a fastidious priss pot who had a definite sense of how his world should be ordered but no sense that he should be the one to have to perform household charms; b) James and Remus would probably be quite happy to live in a disordered and, frankly, smelly mess for the foreseeable future; and c) Peter was the only practical one amongst them. Assuming the Headmaster would eventually bring the house elves around, he set a charm on his laundry to pile itself in the corner and went about life as normal. He reckoned his mum could knit him up a few more pairs if things got desperate.
Years later, when Sirius got his own flat he wouldn’t let Remus spend the night until he had extracted a promise that clothes would not be left strewn about the floors. That lasted about a week. Luckily Remus had since learnt there was one spot on Sirius’ neck, just behind his ear, and was willing to take full advantage of its capacity to distract him.
Lily/James: James’ years as the slovenly one came to an abrupt halt shortly after he and Lily were married. He hadn’t known until then that any semblance of order to her flat had been entirely due to Mary’s diligence. He blamed his ridiculous near-sightedness for that oversight. After about week three the novelty of finding a girl who was more untidy than him wore off and he dug through some of his mum’s books for tips on laundry. People, however, always assumed Lily was the one who kept their house in order and James was perfectly all right with that. Only Remus knew the truth and James’ll always owe him one for never letting it slip.
Sirius/Snape: Picking up socks? Having socks lying about would seem to imply that either of them stuck around long enough after that one, erm, make it three, or perhaps four times.