Hello, Rebecca!
Welcome to the Disney Parks Moms Panel!
Let me first say that your Prince is going to LOVE
Wishes Fireworks Dessert Party! The desserts are truly MAGICAL, and the view of the fireworks is the absolute BEST! I do want you to know that you are not able to see the
Electrical Water Pageant from the Wishes Fireworks Dessert Party area. Typically, the Electrical Water Pageant begins after Wishes Nighttime Spectacular ends. However, I would say you would have a slim chance to see the very end of the pageant if you left the dessert area immediately. (Just know you will be fighting the crowds leaving Magic Kingdom as well.)
My recommendation would be to try and plan each MAGICAL event on two different nights. I don't know if that is possible, but I am not hopeful you will be able to see both experiences on the same night.
If you have other questions, please let me know!
Have a MAGICAL day!
Wes