Students falling in love and having sex with their teachers is quite commonplace. However, a BBC documentary to be shown next week features a male dolphin named Peter falling in love with his human female teacher who was tasked to teach the mammal to speak English.

A clip of the documentary, titled The Girl Who Talked to Dolphins, on YouTube provides clear audio that the dolphin indeed was able to speak English. But no doubt, more fascinating than the ability of humans to teach a language to another specie is the animal exhibiting love and sexual feelings for his mentor.

The two met in 1965 when Margaret Howe, then a research assistant, was assigned to teach the bottlenose dolphin English words for 10 weeks as part of a NASA experiment conducted in St Thomas.

She was supposed to teach Peter to speak using his blowhole. She started by getting him to greet her in the morning by saying "Hello, Margaret." But Peter had difficulty with the letter "M."

On their fourth week, after spending much time with Peter where they did everything together - eating, sleeping, bathing and playing - Howe wrote in her diary, quoted by The Herald Sun, "Peter has become sexually aroused several times during the week."

"He jams himself again and again against my legs, circles around me, is inclined to nibble and is generally so excited he cannot control his attitude around me," Howe wrote.

She said that Peter's desires were hindering their relationship as student-teacher. To keep him focused, Howe said she fondled Peter; if she didn't, the dolphin didn't pay attention to her lessons.

But she eventually admitted, "That relationship of having to be together sort of turned into really enjoying being together, and wanting to be together, and missing him when he wasn't there."

However, she clarified that while it was sexual on Peter's part, "it was not sexual on mine - sensuous perhaps," Howe said.

When the experiment ended and the lab closed, the dolphin was shipped back to the lab in Miami run by Dr John Lilly, the experiment's leader, and his health deteriorated fast. After a few weeks of separation from his beloved Margaret, Peter eventually committed suicide by refusing to breath and sank to the bottom of his tank until he died.

Veterinarian Andy Williamson opined that Peter died of a broken heart.