Actually, looking at Jack standing there in the skin of a wolf disturbs you more than the fact that you're trapped in one yourself. Besides, it'll be easier to cut his off, right? Then once he's free, he can do yours. He's not just going to let you do that, though, and you're not sure how to convince him rationally. But you can think of another way to convince him:
"Jack," you say, staring right into his golden eyes, "I miss you. I miss your tawny hair. I miss your eyes being green, not golden. These wolf costumes, they've been fun for a lark, but that's not you. I want to look at YOU again."
"Really?" asks Jack, "you really mean that? I mean, I wasn't sure if you..." he trails off. "If that's how you feel, then you can cut it off," he finishes. "I can always buy a new one."
Of course, you don't really feel that way about him, right? That was just that one time, at that party. You were drunk, there was social pressure involved, and you barely remember it anyway. You're freaked out about seeing him stuck in the costume, sure, but not because you're secretly in love with him and scared he's been permanently changed into a wolf. That's silly. You just think it's freaky. Right? That's what you tell yourself, anyway.
"Turn around," you say. "I'll start at the back. That'll be easiest." He turns around obediently. You take a fold of skin at the nape of his neck, raise the scissors, and slash into it.
"AWWROOO!" howls Jack in pain, jerking away from you. Is- is that blood? Gods above, what have you done!?
Jack cringes on the floor. His ears have gone flat, his tail bristles, and his teeth are bared. He's whimpering pathetically. You're standing there with a bloody pair of fabric shears in your paw and feeling like a monster. "I'm sorry!" you howl, "I didn't mean to! I'm sorry! I'm so sorry!"
You drop the scissors and approach Jack. He flinches away from you for a moment and snaps at your hand, which is heart-rending. Then he gets himself under control and lets you move close to him.
"I'm sorry," you say again, caressing the fur on the back of his head. "I thought I..." But you're pretty sure you couldn't have gotten any skin. There was just fur and the layer it was attached to. You were being very careful about that.
"Ow," says Jack, who is still in pain but has calmed down enough to speak coherently, "fuck. That really hurt."
"Let me look at it," you say, "so I can see how bad it is. Jack, I'm really sorry."
Jack turns gingerly over so you can see the wound. You're not sure if he's forgiven you for the injury, but at least he trusts you that far. It looks pretty bad - blood is matting his fur, and the wound seems to be a deep one, as far as you can tell.
"Damn," you say, "we'd better do something about this."
Your first instinct is to get him to a hospital. He's probably going to need stitches. On the other hand, how are you going to explain this to the doctor? Not to mention, your other roommate, Luke, is going to be back from his trip later today. What's he going to think when he comes home to find blood all over the floor, and a pair of bloody scissors? Not to mention the tufts of fur!
Deep down, there's a part of you that just wants to curl up and whimper for a while at what you've done. But that won't help anything. You've got to fix this.