Even if Christopher read the contract carefully, Joy wouldn't be worried. Though the contract stated that the loan was in Christopher's name and the interest was high, she could say that she helped him pay it off.
Christopher was completely convinced that he was making a fool of Joy. He believed that Joy was devoted to him and that she would, of course, help him pay off the loan, so there was no possibility of suspicion.
What a great scheme.
Christopher drove the supercar home with Joy. After sitting in the living room for a while, he pretended to take a call. Coming back, he said to Joy, "Joy, there's some business at the company that I need to handle. I have to go now. You must be tired from all the shopping, rest well."
Joy lazily waved at him from the sofa, "Okay, see you, Chris."