We can all see that workplace demographics are changing, fuelled in part by people working longer into their lives, by choice, design or for another reason. The inevitable consequence of this shift is that there will be more instances of older workers reporting to younger bosses. The roles may be reversed but nothing should change in the way that you build a relationship and interact with your boss, no matter what age they are. They are the boss for a reason and they should be shown the respect they deserve. There are a number of other things that should also be taken into consideration if you are found in this situation, to ensure you derive the most value from the circumstances.
If nothing else, remember that working for a younger boss could be just as unusual for them as well and they could be feeling great pressure in managing someone more senior than themselves, so stay positive.
Trumpet Page have some great more tips and tricks for navigating this sometimes difficult relationship. The full article can be found here.
Trumpet Page - How to handle working for a younger boss