We ain't got no place to go, let's go to the donkey show. Darlin' take me by down to Mass, we're going to see someone fuck an ass.
I believe there have been cases of dolphins raping swimmers. and if I recall correctly, there are people who seek out dolphins to have sex with them. and obviously there's the animals that have had poor luck in owners and then the ones they use in acts of entertainment like donkey shows.
I've only read it on the internet, trying to find a news story. I found this video, and from wiki: "Dolphins are known to have sex for reasons other than reproduction, sometimes also engaging in acts of a homosexual nature. Various dolphin species have been known to engage in sexual behaviour with other dolphin species, this also having resulted in various hybrid dolphin species as mentioned earlier. Sexual encounters may be violent, with male dolphins sometimes showing aggressive behaviour towards both females and other male dolphins. Occasionally, dolphins will also show sexual behaviour towards other animals, including humans." and here's a news story