Using ID to get into the nyc pool bar...?

my friend is having a party at the a new york pool bar and i;m pretty much the only one that is still 20. my cousin gave me her ID which looks enough like me but the expiration date is within this year but expired a few months ago. its a PA license so its right there thats the only reason i'm nervous about using it. it's nyc so i can usually sometimes get into bars without id but this is in the middle of time sqaure. i have a back up school id with me that has her name on it but i;m still onthe fence because if i can't get in id have to travel 2 and half hours back home. i don't know what to do