How do I get out of this?

Ok so I found out that my boyfriend is planning on having a suprise party 4 me on my bday 2 morow, and theres gona b a bunch of people that I dont like there. He and his friends invited there friends that I really dont like and my bff wasnt even invited, I found out about the party from my bfs friend, and he said that my boyfriend has worked really hard on this and has spent like all the money he has on me and this party. I dont want 2 go 2 this party, apparently it is at the park and my boyfriend is somehow going 2 drag me down there and there will b a ton of people there. If this party was made by him and my friends I would b happy, but this party was put together by people that I barely know and some that I really dont like. Please help!! my bfs friend says I have 2 go or it will hurt his feelings what do I do??