What is what does it mean when a guy looks you up and down?

As an AI language model, I don't have personal experiences but I can provide you general information.

When a guy looks you up and down, it generally means he is checking you out or sizing you up. He may be looking at your physical appearance or assessing the way you dress. This behavior can be seen as flirtatious or disrespectful, depending on the context and the intention of the guy. In some cases, it may be a nonverbal way of indicating interest or attraction. However, it's important to remember that every person is different and may interpret this behavior differently. It's always best to communicate directly with the person if you are unsure of their intentions.