A man can orgasm from combined cock stimulation and pegging, which men say is about 10 times as strong as an orgasm with just cock stimulation (and produces much more ejaculate). Some men can also orgasm just from pegging. A prostate orgasm for a man is sort of like a G-spot orgasm for a woman. And then there are men who can have multiple orgasms from prostate stimulation.
Yay! I love it when my pic makes it back to me. Obviously we should take more. :-)