There's at least ONE case of a male dolphin orgasm, with a female human as aid (aka. handjob). The study took 10 weeks, took place in 1965, in a partially flooded apartment, where Margaret Howe, a young research associate lived with the dolphin Pete. - not only did they do everything together (eat, sleep, play, etc), Howe worked on a floating desk aswell and slept on a soaked mattress. This way Pete could interrupt Howe instantly, and was constantly encouranged to make more human-like sounds (words).. But as Pete was a dolphin he couldn't speak (duh!).
But as Pete was completly isolated from his own kin, he was getting horny, and began to woo Howe - which means he started to nibble her feet and shins. Of course Howe began pushing him away, and he reacted by hitting her shins, with his forhead, until she bruised. (she would then on wear somesort of rubber boots).
After this initial backfire, Pete went for another love-making-strategy, with much better results ! - He started rubbing her gently with his teeth, with his erect slong outwards her face. This tactic ended with Howe giving him sexual pleasure, with her hand.
(Fun Fact: Afterwards he was much more cooperative with his human-voice-sessions.)
Tl:Dr - A female research associate gave a handjob to a dolphin in the name of SCIENCE
I was going to ask for a source, but Dmitri already posted it. So I put this in my favorites instead. Not that I didn't believe the story in the first place.
I once received a fishbowl with half of that inscribed on it, put my babel fish in it. Turns out it was a message from those dolphins. Some of the oddest things happen to me.
This was an actual experiment where a woman and a dolphin were kept excluded with only each other for a few months. The dolphin constantly rubbed against her and tried to be sexual each time she got in the water. Eventually she gave in. The researcher was disappointed by his conclusions...