Last night, our friends and local social directors offered what one partygoer later described as the “perfect antidote for the winter blahs”: a “serenade your sweetheart” karaoke bash in their living room.   “I’m so looking forward to this,” I told Cyndi a few days before she hosted the party with her husband, Tom. “I’ve been so low lately.” “Me too,” she said. “And I knew I would be. That’s why…