New details are being revealed about Nick Reiner's behavior at a star-studded Christmas party held before his parents' death. According to NBC News, Nick, 32, joined dad Rob Reiner and mom Michele Singer Reiner at a holiday gathering hosted by Conan O'Brien on Saturday, December 13. At one point in the evening, Nick allegedly interrupted a conversation involving comedian Bill Hader. When Hader, 47, said the conversation was private, NBC News reported that Nick appeared to stand still and stare before "storming off." Us Weekly has reached out to Hader's rep for comment.