Should i do it!! please help...?

im 17...my mom told me that i cant go to a party bc i didnt finish the dishes which in fact i did. im plannin on goin to my cousins house ater my laast cl @ 1130 but my mom said she would pick me up from school at 4.. should i go to my cousins house and the party later today? or jus go home and do dishes.????i got a lil over 2 hrs to make up my mind( plus i didnt plan on goin trick or treating this year anyways lol)