Dean was nervous to say the least, but not nervous enough that he didn't have the will to continue. He followed directions. This was Daphne's idea and he wanted to make sure he obeyed her every wish so it didn't cause problems later. He got behind Shareen, placing his hands on her back. Over her shoulders he could see Daphne spread apart on the bed.
Dean's arousal was twitching and jumping impatiently as he waited for everyone to give the go ahead.