[Christmas Sock] That's a lovely idea! A couple would appreciate a thoughtful gift that celebrates their relationship and brings them closer together. If you know their interests or hobbies, you could get them something related to that. Alternatively, you could consider getting them a gift that symbolizes their love, such as a necklace or a pendant with their initials or a special date. It's also important to consider their personalities and what they would truly enjoy. If you're unsure, you could always go with a classic and timeless gift like a beautiful set of matching pajamas or a romantic dinner out.