Can you help me make a decesion it might hurt somebody? help me?

k so the other day my friend came up and asked if i wanted to go to his superbowl party with a lot of people. the next day my other friend came up and asked if i wanted to go to his party. his names Jay. jays party sounds funner and i want to go to it but what should i say to the other kid that i cant go i dont want to lie and he asked me first and i said ya. so idk what to say help