OMG MY BOYFRIEND IS SOOO ANNOYING :@ HELP?!?

ok so for my birthday I want a bouncy-castle partie, and yes before you ask I'm 18. I rellly want a bouncy castle like this for it > http://www.taylormadebouncycastles.co.uk/bouncy-castle-hire/pink-bouncy-castles.jpg, but my bf is bein too tight with his muney :@:@ i wanted it so me n the gurlies cud hang out on there n impress my hot neighbours by bouncing...if u get wot i mean ;) any ideas how i can get my bf to cough up the dosh? xoxo