Originally Posted by
offerendum
In reality some hotels ask for an ID of one guest, but normally not for the second person.
Yeah, that's consistent with the USA practice. It would be unimaginable for a clerk to ask to check the ID of your teenager.
I have noticed that this "extra guest" fee can make a big difference in travel cost if you happen to have a high school senior or college-aged child along with you on a trip. It's kind of a nuisance. In addition to paid rates, it seems to severely impact the value of hotel award stays (like using your points isn't too worthwhile if you have to pay an additonal $50 or $75 for your teenager).
Indeed, the only time I've ever been questioned about the age of my teenagers while travelling in the USA is at the AMEX Centurion Lounges. They've just changed the rules anyway, but I made sure to get them their own cards (I didn't have to pay for them) so they wouldn't be hassled.