It depends on the value. You are allowed to gift $14,000 to any individual in 2017. If the value is less than $28,000, you can considered that you gifted the remaining balance to his wife. Any amount over the $28,000 will require a Form 709.

Form 709 

The purpose of IRS Form 709 is to report gifts that are subject to gift and generation-skipping transfer taxes. 

The most common rule is the annual exclusion, whereby anyone can give up to $14,000 in cash or property to a person without having a taxable gift. This is the provision that prevents most ordinary holiday or birthday gifts from being taxable. 

Even if you have made a taxable gift, Form 709 isn't as big of a burden as many think. That's because unless you've made a huge gift, you won't have to pay any actual gift tax.