Reveal to our son

Katie

I’m 20 weeks along and my husband and I will go in for the ultra sound early next week to find out the baby’s sex. Our 4 yo will be at school so he won’t get to hear. I was thinking about bringing home a cupcake or something small to announce it to him, but I’m feeling like that might be contradictory. He’s at the age where he’s starting to say “that’s a girl show” or “these are girl toys” and I always tell him “there’s no such thing. There’s just stuff you like and stuff you don’t like” so I’m trying not to have any colors he too associated with any sex. Any ideas? TIA