apparently I'm inviting too many people to my baby shower

My boyfriend reckons there shouldn't be more than 10 people at a baby shower. I have written a list of half my family, some friends and close Co workers and it adds up to 25 people already. He's staring at my list asking why I can't cut down the list,since not everyone is going to make it. Plus we don't have enough seating apparently. We never have enough seating at any family events, but make it work. I can't not include my family as it is or the few friends I have. What to do??