Boyfriend's Christmas Party

Every year my boyfriend's office throws a Christmas Party. Well this year's invite just got sent out and he only RSVP'd for one. Therefore I'm not invited. When I asked him why he said because he likes to keep his work life separate from his personal life. I feel hurt by his decision, as I'd jump at the chance to include him and to have him meet my coworkers. Am I right to be upset? Or am I overreacting?