Santa's Stocking

To ejaculate into somebodies sock as a practical joke

After sexing your missus,pull out and come in her sock and reply "Santa left you something from his fat sack."
Or
On your best friends mums birthday jack off into one of her socks,and reply
"Santa came early this year"
Or
Your bosses sock,friends sock,etc

Now that you know what a Santa's Stocking is, it's time to spread that Christmas joy, regardless of the time of year.