Samhain Publishing has a Christmas short story for each day of December. You can find them here. I assume there will new ones coming each day. They are all free and in pdf format. Each is listed as Sexy or Sweet.
Samhain Publishing publishes the following genres: Action/Adventure, Chick Lit, Erotica, Fantasy-Sci-fi, Gay-Lesbian, Historical, Horror, Inspirational, Interracial, Mainstream, Mystery-Suspense, Non-fiction, Paranormal, Urban Fantasy and Young Adult plus a bunch of Romance.