Their are friendly animals and then there are the animals that are perverts. This has happened to in real life where animals will try to get it on with whatever random human comes by them. This is common with dolphins. For this trope all instances are non consensual.
This Trope only cover's non sentient lifeforms
compare Interspecies Romance
- In King of the Hill Hank get a free trip to the aquarium to swim with dolphins. Hank seem to be getting along with the dolphin fine, but eventually it becomes aroused by him and tries to mate with him.
- Sealab 2021 had ones riled up by menses.
- In Garden State Andrew Largeman has his leg humped by a dog while he is in the doctors office.
- The dolphins of David Brin's Uplift Series are more than willing to get all kinky with people. Mostly for giggles. Also because they're horny.
- Dolphins even show up in Shakespeare: "Why, your dolophin was not lustier!" Dolphins have a reputation.
- in both reland and Britain, swimmers with dolphins have been booked on indecency and bestiality charges for, er, being obliging to dolphins with erections, and providig a helping hand (or in the case of the Irish woman, other bodily part) as needed. Another good reason for dolphins to evolve those hands and opposable thumbs?