Sleeping on the Back

Summer did not want to go to sleep last night, and she is getting a little attitude about laying on her back, I mean come on kid, you slept on your back for the first six months of your life, what is wrong with your back? I mean, I don't mind if you want to sleep on your stomach, but I have to lay you in your crib on your back and you can roll over and get comfy, you don't have to do it in a way that says, mommy you are an idiot, and immediately fling yourself over onto your side and act like I don't know what I am doing .... SHEESH