My Dad found a hidden camera of mine. HELP!!?

-I hid my iPhone in my sisters room to preform a prank on her and use it as a camera to know when to go. But my dad went into my sisters room to fix something and found it, but didn't tell me or my sister. When I went to check it I found it gone. He is NEVER going to believe me if I tell him it was for a prank. What do I do!?!? I don't want him to think that I am trying to spy on my sister undressing (which is probably what he is thinking as this has happened before). I don't know what to do. If he is thinking that I was trying to use it for bad, there is NO way to change his mine. He is not easy at all to convince. PLEASE HELP ME!! WHAT DO I DO!!!!



P.S. My phone is in airplane mode to save battery as I was going to be leaving it recording for a while.What kind of prank would involve you filming your sister? That's pretty weird. If your dad brings it up, you could always pretend you lost it or something. Or you could always tell him the truth- just a thought.
I used this bathroom hidden camera before, it's pimp. I got mine from hb. Check out the link
Swear on something really important such as your life.
Yea right u perverted creep........is she hot?