How do I win my boyfriend back?

I'm 16 and he's 15, but I really love him. I cheated on him with my ex-boyfriend about two months ago and we've been talking still and we still hang out and hook up all the time, but he's a little messed up. He was in the mental hospital for a week recently and is on a lot of meds and his parents hate me and he's not even supposed to be talking to me, let alone seeing me. He told me that if I do something crazy and amazing for him that no one's ever done before he'll take me back. I really need to be with him so I have to do this. I only have two days to do it. He really likes sailing, swimming, anything outdoors really, the color orange, bread, movies, and I just need to think of something to do that no one's ever done for him before. I was thinking maybe in the morning we could go for a picnic on a boat and then go back to my house and watch movies and just hang out, but I don't know if that just sounds too boring and also I don't really know if I can borrow someone's boat for the morning.