What does this mean "perchè due non fa tre"?

Demi is a bit bigger than her boyfriend wilmer

I can't muster a proper meaning, but the sentence is "because (or why) two does not three"

Not sure what perchè means but the rest is two don't make 3

Perks of knowing a Romance language

Because two doesn't make three?

delete it fa tre

Wait perchè does mean because. In Spanish it would be porque, in French parce que

Well I know what the words mean but I think it's some kind of proverb

literally "Because two doesn't make three", it's a way to reply to something without actually explaining a reason why.

"Why did you do that?"
"Just because"

Another way would be saying "Perché sì" (Because yes / because I say so) or "Perché no".

This makes more sense than anything I could think of.

Because when answering, why when used in a question

Allahu akbar

Interesting

I feel like it'd be a way to reply to a statement has no logic