Do you want it to hurt?

[Anahki]

As we see here, there is a large range of preferences. You can make it painful, or not. It is your story, your characters, your aninal TF and your universe, entirely yours.
From my point of view, if you want something realistic you should absolutely go for the pain option: have you ever had a small rib fissure? It hurts like hell when you breath, and it is not even a broken bone. Imagine that your inner guts, muscles and bones start resizing inside of you... yes, you can add endorphines and similar and imagine that along with the inner guts reformation your body excretes drugs to cope with the TF... but that could not supress the pain, only would prevent you from dismaying. A fantasy element is better accepted when it is surrounded by some degree of realistic stuff, otherwise, it would obviously look "unrealistic".

[OhZone]

Only guys are allowed to answer? :'(


Anyway, I like the idea of shared pleasure and transformations of all kinds are more fun if they involve pleasure IMHO

I mean I love s/D but not S and M.