Desperately need your help with this :) please..?

my boyfriend Keegan and I have been dating for seven months, and he asked me to his school's homecoming dance a few days ago. I want to ask him to MY school's homecoming as well, but I don't know how to do it. :( there's a garden full of beautiful and colorful flowers with a gazebo in the middle....and this garden is by my house and it's where I wanna ask him. I just don't know HOW to ask him. I really need your help. like desperately. :) if you have any cute ideas in mind, please let me know! thanks a bazillion:):):)