Should you always be able to have first dibs on your own birthday cake?

You should definetly get the first piece but if people want to finish your cake they should be able to because I honestly think that is rude to keep the last pieces for yourself you should get a big enough cake that you always have leftovers. Honestly I have never had that happen to me I have always made or bought a large enough cake for every party that I have had and if your having 50 guests then get a cake or dessert big enough for 60 people have a great birthday.