R.
Honestly, your child won't really even eat the cake. We bought a "smash cake" specifically for my daughter. My daughter took one little bite and hated it. She wasn't used to cake, since she NEVER had it. Up until that point she had fruit, veggies, some meat, and goldfish crackers!
Your child will play with it, get it on his face, roll it around his tongue (if he even really tastes it) and you'll take a bunch of pictures. Why should everyone at the party suffer through eating a "sugar free" cake because of your son? I understand the principle of keeping children healthy and providing excellent nutritian, but this is a BIRTHDAY. It happend once a year! Your hubby can't budge?
Good luck--and enjoy a great first b-day with your son!