One of my four was like that. It was time for nursery school, and I explained to him that the diapers had to go. He was very verbal, and said “NO”!
I said “YES”, and “RIGHT NOW”.
The little pisser held his pee from very early in the morning until about 5 in the afternoon, and begged me to put on his “Pampers”, so he could go pee.
I said “NO”. “Toilet from now on, Buddy”. Much wailing, kicking, etc. After about 45 minutes, he realized I meant business, peed in the toilet and never asked for his “Pampers” (appropriately named) again.
He turned out to be an outstanding man, by the way, now 45 years old. I am very proud of him.
How sweet!