No, Steven was just being humorous.

Steven Quartz Universe is his full name, but the rest is just what he made up.

I haven't seen any of Future (sadly 😭) but his actual name is Steven Quartz Universe and the other names are from different episodes:

• "Cutie Pie" was given by Garnet in the episode "Future Vision" when she says "That's a lie your middle name is Cutie Pie"

• "DeMayo" was in the episode "Gem Harvest" when Steven discovered that Universe isn't his real last name, Greg has changed his name from "DeMayo" to "Universe"

• "Diamond" was supposedly given to him when he discovered that Rose Quartz was actually Pink Diamond

@MiraculouslyEm14 In Future, when Steven went to the doctor, the paper said his middle name is "Quartz Cutie Pie DeMayo Diamond"

@SpeedyDragonJ why isn't it in the article then?

.

Eh

@SpeedyDragonJ in Together Forever and Growing Pains articles it's pointed it's a joke, so...is it?

I forgot