Sweet AND sexy things to do for my boyfriend?

We're ALWAYS doing sweet things for each other, but really sexy things, too. So can you give me some new ideas? I've got one of his old shirts that I wear around, and he likes it because it lets people know that I'm "his" xD I find this sweet actually. And then he also says pigtails turn him on...I laugh at this, but if he likes it, then alright. So other ideas would really help, please?