I once had great sex with a young punk guy and just before he orgasmed he warned me that he has "pretty intense" ones--did he ever--shook, spasmed, and quivered for quite some time after he came. It was delightful to watch and know that I did that too him. Was also vocal, so I got some admiring looks the next day from my college age neighbors across the hall--had wished that they came over for the same treatment.