Diapers aren't mandatory. That'd be super silly.
I'm a little and have been for quite some time. I'm in a stable Ddlg relationship. Daddy has never asked me to wear diapers and I've never chosen to do so.
Ddlg doesn't have set rules. It's about being your inner yourself. Be your true self. If they aren't comfortable then don't give the thought a second moment and move on to fun things for yourself.