You go along with it, because it DOES feel good! As he pumps up and down your vulpine cock you start yipping out with pleasure and yiffing like a real fox. It turns both of you on. As you orgasm all over Jack's new facial fur you feel your ears strech out and become pointed. Even after your first release your cock is still rock hard. Now you've got hold of Jack's enourmous canine cock and the two of you start working each other.
The two of you cum together as if on cue. Jack's now got a slew of wolfish features now. His whole face is that of a wolf's now, including a muzzle with a large pink tongue. The rest of his body remains mostly human, however, his hands and feet are now much like paws.
You on the other hand have fewer features, pointy ears, a wet black nose, and paw like hands. Your hair has changed orange but your fur has still yet to grown in as much as Jack.
Lying on Jack's bed you enjoy one more feature completely changed on you. Now you and Jack both have complete tails, which are currently interwined between the two of you.
"I love you..." Jack whispers in your foxy ear.
"I figured you were going to come out tonight, just not like this..." you chuckle lightly under your breath.