He didn't sing badly, but the song choice was wrong for him. It was blatantly obvious that Louis had advised all his acts to answer Simon back. I'm not sure this is wise - sometimes this comes off, sometimes it doesn't. As for the Sharon thing, it is becoming a tad embarrassing, but that is wholly Sharon's fault, not Shayne's. She has put him in a no-win situation, where he has only three options - a) respond playfully, b) become all embarrassed and tongue-tied, or c) act outraged. Any one of those responses would elicit negative feedback from the public. I think the best way for Shayne to handle it would have been to play along at the time and speak to her quietly afterwards, asking her to tone it down for next week. But then, he IS only 20/21, so perhaps he should ask Louis to speak to her about it. I think either Simon or Louis should speak to her about it in any case.