Please help, I have a question that didnt fit so go to details to see, and I really need help?

i have 2 barmitsvas on one day. one is someone who youst to bee one of my best friends, but know is just a friend. He is having an ordinary bar mitsvah. i already responded yes to it before i got the other invitation. the other kid im not really friends with, but hes rich, and having his party at a knicks vs. mavericks game, and before the game we get to meet the players, and get their autographs. i can still tell my friend having an ordinary party that i cant come, but then i might lose a friend what do i do?