Your employer is not responsible for the initial action by a customer: they had no way of knowing what he would do, and therefore are not liable for it. But now that they know, if he continues to act inappropriately and they force or require you to keep interacting with him, that could be considered sexual harassment which they, due to their foreknowledge, would be liable for. So if inappropriate behavior occurs again, you may have a legal claim and could contact the feseral EEOC or your state's equal or civil rights agency to file a complaint. But if nothing further happens, there is no employer liability, even if you are "uncomfortable" around this person--liability is based on action or behaviour, not your subjective comfort.You could in theory file a police report for this, but the authorities are almost certain to take no action for a one-time kiss.