This time last year, I shared my recommendations for the most fun and flirty solo Halloween costumes for vintage fashion and media lovers. This year, I’m back with a twist: group costumes. While solo costumes are sometimes the most iconic, it can be fun to participate in a group costume. If you are lucky enough to have friends or a partner who have the same old-fashioned interests as you — or are generous enough to indulge your nerdy interests — Halloween is a perfect time to celebrate together.