If your real ID shows you to be underage why would you bother showing it to a bouncer/cop?

I've worked the first part of that job plenty in my youth and underage guys would just mumble something about forgetting IDs or walk away once they saw IDs being checked at the door. I can't recall one just saying "here you are I just wanted to show you I can't legally come in here. Thanks!" What would the point of that be?

To get beat up by the alcohol police! Geez

The question remains why he would use a real ID showing him to be underage. I suppose it could just be sheer carelessness in that he picked the wrong one up from his dresser on his way out and left his fake ID at home. Or perhaps he knew other bouncers at the same place and had been able to get in with an underage ID before but hadn't planned on finding an unfamiliar guy at the door. Perhaps this bar doesn't always check IDs. These are certainly plausible, but still raise the question of why he would get all the way within grabbing range of the bouncer before noticing either. It's unusual behavior. Again the "nah let's go somewhere else" turnaround is the norm in these cases in my experience.

It should, but in this strange area of professional outragees apparently doesn't, go without saying that this does not warrant violence in return, so I guess I need to waste keystrokes saying it. I have seen obvious fake and "missing" and borrowed IDs from older kids who look nothing like the one in front of me many times. My response of "Nope can't let you in" has always been the result rather than a take-down on concrete. Just never come across somebody waving an underage ID at me for no apparent reason. My response would have still been the nope not the bodyslam, but can't say it ever happened.