Jack takes you out on a walk in the park. You're a big shaggy dog, and he's your master, whom you love, and love to obey. You mark some territory, roll around in the grass, chase birds, catch some frisbees, and generally have a great time.
The two of you are laying on a grassy hillside, just relaxing. Jack rubs your belly and you pant, closing your eyes in enjoyment.
That's when it happens: your body shudders, and your vision tunnels as your mind swarms. Soon, everything goes black.
When you wake up, you're human again- you're yourself, and you're wearing nothing but Jack's jacket around your waist. The two of you are still in the park on the hill, and Jack's looking at you with concern.