Its possible that humans wouldn't recognize that sort of extremely specialized tool if designed by/for another species. Or if its etherial, like bubble nets.

I'd say look at courtship behavior "Pick me, I'll make this fun!" and veterinary records, to see how often non-etherial tech stuff gets stuck where it shouldn't. (Also, maybe look at sexual behavior while participants are high on pufferfish, and I do mean literal pufferfish, no pun).

If dolphins are like humans in regards to sex, they'll boast of their best tricks while peacocking, end up with far too many instances of 'You have what stuck where? I don't think I wanna know...", and be very uninhibited while on drugs.

It does sound like they might use sex to bond (like humans and bononos) but I don't know if it has the same correlation-not-causation pattern as humans. Then again, the entire species of humanity has a lot of very different ideas on how to do friendship, love, sex, and marriage, and most of those ideas are somewhat incompatible, so who knows?

Octapi on - I think it was cocaine - get very cuddly, interestingly enough.