How to ask???

Okay this is gonna sound crazy but I want to do it a cute way..

my soon to be nephew ( I consider him my nephew anyways I’ve been with my fiancé for 4 years ) is only 5 months old but when we get married he’ll be 2 years old. I wanna ask his parents ( he’s too young to ask himself ) in a cute way for him to be my ring bearer. I don’t wanna just text his mom and say “ hey I want him to be my ring bearer “ I want to ask in a cute neat way. Maybe with a card and something they could keep. Please don’t judge me haha. Again he will be 2 years old when I get married so yeah.