Transcript for What Would You Do: Young man verbally berates elderly waiter
Reporter: It's lunchtime at the northvale classic diner, in northvale, New Jersey. Hey, how are you? Good, thanks. Great, I'm Mike. I'll be your server. Can I get a coke and the classic burger? Coke. Okay, do you want diet, regular? Ice, no ice? Ice is fine. Just regular. Okay, with ice. And you said the classic burger, sir? Yeah. I didn't know if you know this, but it comes with grilled onion, American cheese -- I know, I read it on the menu. Okay, so, let me put that order in for you. Do you want anything else? Like a salad or an appust the burger. Just the burger? And the coke. Okay, great. I'll be right back with that. All right. Reporter: This customer has ordered what he was hoping would be a quick bite. But as the minutes tick by, he's growing hungrier and more aggravated with this senior server. Here'sorange juice, sir. I asked for a coke. Do you realize how long I've been sitting here? I'm sorry. I do see that you ordered a coke. I'm kind of in a rush. Can you speed things up a little BIR. No, I'm sorry that I sat in the section with the older waiter. This is some of the worse service I've ever had. Would you mind just repeating your order one more time? Reporter: Do you condemn the customer or agree that the waiter needs to work a little harder? Maybe it's time for you to retire, grandpa. Reporter: What would you do? Okay, sorry again. So, this is the classic -- You still got it wrong. Reporter: Lucas' line of questioning is leaving a bad taste in the mouths of the diners. Seriously, how old are you? I'm 66. 66? Okay, so you're getting to that point. Shouldn't you retire? Isn't it that time? Well, I kind of am retired. I need this job and this money so -- Well, you should have planned out better, because you're not going to make it too long as a waiter. This is just ridiculous. Reporter: And things quickly escalate to a point that this customer can't just sit by and watch. You orderedssic, and that comes with -- Grandpa, stop telling me what I ordered. Listen, I ordered the classic burger. It has roasted peppers, it has onions -- What can I do to make it better for you, sir? Give him a break, bro. What do you mean? He's getting my order wrong like crazy, I mean, this is -- I know, but he's trying, dude. I mean, like, I ordered my thing three times and he just keeps getting it wro All right, so, he made a mistake, but you're getting on his case. Listen, why don't you just go back to your seat and let us talk, okay? But you're getting on his case for no reason. No, I'm getting on his case because he messed up my order, like, three times. I'm sorry. Why don't you just get up and go to another restaurant? Reporter: Time for us to step in. All right, my man. Oh, no! Reporter: How are you? John Quinones, baby! We watch you. Reporter: Thank you, thank you. I'm so glad nothing's wrong. Look at my hands, man. Reporter: Wow. Babe. I felt sorry for that guy. It really bothered me. And if there's one person that would be on this show, it would be my husband. He speaks his mind. He speaks his mind. You're not getting a tip out of me. You're too old. I'm sorry. Reporter: Some have no problem confronting our rude customer head on. You're being very, like, abusive to that waiter and if he's got it wrong, maybe you should eat somewhere else. He's old and he's slow. No, it doesn't matter. You're being inappropriate. It's making me uncomfortable. Reporter: But others are so upset, they ask to be moved. Is everything all right? Yes, we're just going to sit somewhere else, is that okay? Yeah. I'm sorry, did I -- No, no, no. He's just being hard on me. Exactly. And I can't take it. I can't just sit here and listen to this, so, I need to change my seat. Reporter: Tired of the insults Lucas is dishing out -- Is there another waiter who isn't 100 years old? Reporter: These customers deliver some words of advice to our shunned server. You should complain about him. In the future, if that happens to you, have another waiter take care of him. Take care of him. He's going to get me fired. I hope that's not the case. He won't get you fired. I'm sorry, I'm just brand new. He's obnoxious. I'm going to tell the manager that he's -- He is exactly, well put. Reporter: And then that diner follows through on his word, speaking out against our inconsiderate customer. He's an idiot. He is? Yeah. What happened? No, no, no. He's just acting like a moron, okay? So it's not this gentleman's fault. Reporter: Time for us to talk to them. How you doing, guys? I'm John Quinones. They were actors. We were wondering who would say something. Well, you're lucky you jumped in, because I was a heartbeat away from inviting him outside. Reporter: You were that upset? Well, it's just flat out disrespectful. And there's no reason for that. Man, are you an idiot? You got my order wrong, again. I'm sorry. Reporter: This family dining at the next table takes note of the situation. Here's a tip. It's time to retire! Reporter: And they try to reason with the discourteous diner. Listen, you should be a little nicer to that guy. He's like an old waiter. He's trying to do his job. I got my granddaughter here, you should be teaching her the right thing. My dad's here, he's looking at you, like, what's going on? I just feel like you shouldn't hire people that are older like that that can't remember certain orders. Maybe he needs the job. Maybe he's got bills to pay. Be nicer. He's learning, he's learning. You'll make his day and then he'll pass it onto the next guy. Reporter: With four generations of his family looking on, he tries to use the situation as a teachable moment for his family. Say be nice. Tell him to be nice. That's not fair! Be nice. Be nice! You guys are right. You guys are right. I'll loosen up. Thank you. Enjoy your lunch. If it's that bad, you can come eat with us. Reporter: Before Lucas joins them for a bite, it's time for us to say hello. You actually invited him to sit with you? Yeah, why not? Maybe he was having a bad day. Maybe we'll change his whole attitude. Reporter: What'd you tell him about your granddaughter? I said, she doesn't want to hear that. She wants to be nice to people. That's what we want her to learn. How to treat people. He just got a job at his assisted living. He's working in the store that they have there. Reporter: And if somebody said to you, you're too old to do that, what would you say? I said, I'm very lucky. I don't feel that old. Reporter: Right away, these final customers are shocked by the questions and the comments Lucas is hurling at the waiter. Could I ask you how old you are? How old am I? Really? Yeah. I mean, to be honest, you're really slow. I just want to make sure that I leave today. I'm sorry. If we wait like this, I'm going to be as old as you -- You're really rude. What was that? While she goes to talk to the owner about the diner's bad behavior, these customers stay put to take on Lucas. What did she just say? She said you're being rude. She said you're being rude He's slow and he's old. How long have you been here? Ten seconds in. No, I've been here for awhile. You are rude. Come on, he's an old guy. He's not an old guy! Who the hell cares if he's old or young? You are still a rude young man. And I use the word "Man" loosely. Are you for real? You might not realize that, but you're asking those questions, your behavior towards him is rude. It's arrogant. Reporter: We step in. Hi there, how are you? I'm John Quinones, and this is TV -- Get the hell out of here. Reporter: You were amazing. I'm so mad. Reporter: Why? Tell us. I'm very upset. Reporter: Some people were concerned about how he might react, so they didn't do anything or say anything. But you -- No. No, I didn't care. I'm a young -- I'm a little older than young, Sicilian woman. Reporter: The Italian in you? It's the old Italian in me, and you just don't do that to older people, or anyone, older, younger, anyone. Reporter: Then we make our way over to this couple, where we find out that this man works for our very own ABC news. Full disclosure, I'm a senior producer at "Nightline." Reporter: Little did he know, today, he'd be caught on our hidden cameras. You treat anyone that way, it was just so not right. Almost like he didn't realize how rude he was being. I looked at him like he was my kid and, maybe he needs to be
This transcript has been automatically generated and may not be 100% accurate.