I'm thinking of making my boyfriend a party hat with a twist: it'll be made out of his dog's skin!
His dog? That's horrifying! Why would you skin his dog as a gift to him?
It would be revenge for him cheating on me.
Thinking of skinning an animal to get revenge on your boyfriend is cruel and could lead to legal problems. Instead, you should seek professional help for your anger if cheating has led to you to desire hurting an animal.
I want to hurt my boyfriend. I'm just using the dog to do it. I'll slice his face and make hats out of it.
Killing a living creature as a means to hurt a person is bad. The dog did nothing to deserve it, and such an extreme act of revenge isn't healthy. You should look into counseling, and you should think about to breaking up with your boyfriend if you hate him that much and he's unfaithful anyway.