How can i convience my mom i want my belly on periced?

well im 15 and i turn 16 in august. i always wanted my belly on periced but never came out with it intil now!! some of my friends have theirs done but the reason why i want it is because i HATE my bellyon!!!!! its really big and i just want to hide it in my swimmin suit. my mom usually lets me do whatever i want but my dad is totaly against it and shes starting not wanting me to get it......so can any of y'all give me advice on how to convince her? i really want this done y'all so please hhhhheeeelllllppp!!!! :):):)