Consent before shifting...I dunno, depends on worldview. Sometimes, the human self or soul and the animal self are clearly two separate entities, and in some 'verses, they are not.
I think, even if the human part gave consent, if the animal part was frightening or unwilling, it would be...rape. I dunno. Rapiality? Beastirape? Hmmm.
But if the animal part were participatory, then it would be consensual, if fuzzy, sex.
Huh. I'm just going to say it's safer, all the way around, to avoid sex altogether with shifted shapeshifters.
Other non-human sentient creatures, well, I guess let you tentacled, disembodied, multilegged, slimy, dry, rocklike, whatever freak flag fly.
And now I have to dogsit. And feel vaguely guilty.
Yep, the first thing I think of with dolphins is dolphin humping human stories. Seriously. So weird.
I'm going, I swear...
Didn't Alyson Hannigan say she wanted to do a dolphin? Or am I just making random stuff up?
What if they gave you consent before they shifted into their non-sentient form?
IIRC, you still warn for the big B when you post the fic.
Look, it's possible that it was a thing a few weeks ago in my main reading fandom, okay?
Wait, what?
Yes. A lady getting impregnated by a dolphin, IIRC. It snuck up on me in some anthology.
A friend of mine who had some minor success in the comic book field passed on this bit of wisdom about becoming a success: you have to have at least 2 of these three qualities: be good, be fast, be nice.
I'm screwed.
ETA: But not by a dolphin. Just wanting to be clear.
Stormy, Mon Amour -- you can see it described here: [link] but I read it in Tart Noir.