If you are an American man traveling in France or Germany find out where the 16 year olds hang out and try to chat some of them up. Really try to get them in bed. You’ll very quickly find that you have no magic brainwashing powers.
16 year olds can legally consent there, so you’re not breaking any laws. And don’t worry, you won’t get anywhere anyway. Unless you are very rich, or extremely good looking, 16 year olds will have no interest in you. And they are not vulnerable or easily manipulated at all.
If you’re charming and good looking a few might flirt with you for a while. Some will tell you straight out to buzz off. If you’re a sympathetic type, a 16 year old young French woman might tell you “No thanks, but try Marie. She’s kinda slutty.”