Interesting post. While clearly no FA (or anybody) should do things that make people uncomfortable, let me ask a few questions to try and get a better idea of what happened here (I hope these don't offend you, and obviously feel free not to answer):
- Are you gay?
- Do you think the FA is gay?
- Are you or the FA above average in terms of physical attractiveness?
- Did you or the FA give any flirtatious vibes to each other?
- Did the FA act this way with anybody else?
- Are you American or have spent many years in the US?
Of course, the answers to the above questions do not excuse inappropriate behavior, but they might help to shed light on the situation.
Based on what you said, I would not suggest you involve any police/LEO in this. If you feel so inclined, it might be a good idea to send an email to US about this. With any luck, they will file this with the necessary people. With any luck, if the FA in question has a 'clean record' in these types of matters, your email will be ignored. If the FA in question has received similar complaints, action should be taken.