Replying to Help convince my parents to let me have a 18th bday party WITH alcohol

so my parents are almost letting me have a party at my house for my birthday. i turn 18 january 2 btw. i gave them a number of 20-25 kids.

they are kinda scared to do it cuz they dont wanna get arrested.

i told them that we put up signs that say "no drinking unless over 21" so they cant sue. drivers either sleep over ordont drink.

does NS have any ideas to convince my parents