The SECOND- nay, the INSTANT my feet cross the threshold of my home I take off my shoes and socks. i can't stand my shoes being on at all, and i have NEVER been in just socked feet- and i've lived in very cold climates. I can't stand my feet being in shoes- they go on just before I walk out the door, and not a moment later. If i go somewhere where footwear is not needed, like to the beach, i leave barefoot, drive barefoot, and get home barefoot.
I've actually turned down quickie-sex at times because removing my shoes and socks was not an option due to time or setting.
Besides that, I can grip the bed with my toes- makes thrusting more interesting when you can thrust your whole body instead of just the hips.