I need help

For Christmas my wife gave me a box that on top said "My Cuckold Stuff" and inside the box was a pink lacy thong, a leather collar, handcuffs, chain a notebook, a golf pencil and a soft tape measure like a tailor uses.

My wife told me that I was to put the thong on after my shower on friday and keep them on until Monday morning. She also said that as soon as I got home from work I was to give her the chain and handcuffs and at all times while in the house over the weekend I was to wear the collar. She said the measure, notebook and pencil was for me to keep a record for her.

I had no idea what she meant and she told me that by Saturday monring I would understand. Well yesterday while at work I googled cuckold (how I found this site as well) and found out what it meant. Last night I told my wife in no uncertain terms that I was not going through with it. She just laughed at me and patted my cheek and told me it was a choice that I really didn't get to make.

What should I expect? How do I convince her that I am not doing this?