Mittens, Mistletoe, and Magic

AU - The night Voldemort attack James sacrificed himself instead of Lily, and Lily lost her memories. The fact she doesn't remember Severus calling her Mudblood meant a second chance, but taking advantage of her lost memories didn't seem right. Four years pass, and Severus finds himself invited to Lily's Christmas dinner with her family, and Remus, and goes without expectations.