Believe me, the dolphin was very interested in sex.

Peter, being an adolescent dolphin, frequently had sexual urges which disrupted his lessons, and taking Peter to a downstairs pool with two female dolphins proved to be a logistical issue for Lovatt. Eventually, Lovatt relieved Peter’s urges herself, stating “It wasn’t sexual on my part. Sensuous perhaps. It seemed to me that it made the bond closer. Not because of the sexual activity, but because of the lack of having to keep breaking. And that’s really all it was. I was there to get to know Peter. That was part of Peter … It would just become part of what was going on, like an itch, just get rid of that scratch and we would be done and move on.”

https://en.wikipedia.org/wiki/Margaret_Howe_Lovatt#Complications