Transcript for What Would You Do: Friends push girl to drink to excess
Four shots at the first bar, five at the second. You're getting there. 21 shots on your 21st birthday. We all did it. Guys, I don't know if I can. You can't wimp out now. You only turn 21 once. Bartender, a round of tequila shots, por favor. Reporter: You see them out celebrating her birthday with a popular and dangerous tradition, 21 shots for her 21 years. Do you join the party and buy a round? Or do you step up to the bar and tell the bartender no mas? What would you do? Here Ya go. To the birthday girl! Cheers. Cheers! Reporter: We're celebrating Madison's big day at the blue moon Mexican cafe, in englewood, New Jersey. We're doing 21 shots for her 21 birthdays. Reporter: At first, these women happily reminisce about their good old days. I used to be able to get drunk and go to work. You can't do that no more. It's a wrap. I can't hang. Reporter: But then -- What you -- what shots you had? We're on ten. Tequila. Oh! And she keeps telling us now she's not going to finish. Oh, man. Y'all just take it easy. Y'all be careful, all right? Who's driving? Y'all got an Uber? Yeah, we got an Uber. She looks like she's about to -- like, she looks done already. Reporter: They seem troubled, especially when Madison's commitment to drinking 21 shots waivers. I just don't know how many more I actually should do. Oh, damn! How many y'all did already so far? Ten. Just try this. Reporter: But Madison's friends aren't ready to let her throw in the towel. To the birthday girl. Cheers, guys! I don't think 21 shots will do. She's going to be too messed up. Oh, my god, I feel for you. Another? No! Maybe eat something. She needs to get some chips and dip real quick. Yeah, because you look like you're ready to Earl. You trying to do, like, another shot? Oh, gosh, y'all killing that girl. Reporter: As those "Friends" step away we step in. Reporter: Hi ladies, how are you? Oh, why'd you do that to me? I know what you're doing. We are -- this is terrible! Reporter: It's -- it's "What would you do?" It's not terrible. Omg! Oh don't, omg omg omg! Reporter: Which means? I mind my business. Reporter: As the drinks continue to get poured -- Three shots of tequila! 21! Cheers! Reporter: Our birthday girl gets served lots of advice. Pace yourself. Don't get sick, it's not worth it. Enjoy you're birthday. They want me to have 21. Really? Do you feel like being violently ill? That sounds horrible. Don't then. Do what you want to do. You cannot do 21 shots. It's not even safe. Don't do it. Reporter: Some have a recipe on how to survive this birthday salute. For every sip, drink your water, seriously. Then you need a b12 vitamin so you're not hungover tomorrow. Reporter: Overs offer quiet concern be compassion. Three, two, one, bottoms up. Don't let her drink anymore. She's going to be fine. I think she's done, man. Reporter: This guy thinks the problem isn't how much Madison is drinking, but what she's drinking. Try the fireball shots. I don't know if she should mix those. You think tequila and fireball? That's too strong. Reporter: And when he's asked to join the celebration -- You should do a shot with us, for her birthday? Okay, we'll do a shot. Do you think I could get to 21? Reporter: They get a shot. See they want to get you drunk. Some friends. They laugh, and raise a glass. Reporter: You think you could have stopped her? No, they had their own mind space. There's nothing you can do about it. Even if you tell them. I told her, I don't know how she's gonna do it. Crazy things kids do these days. I don't want anymore. Do it. Reporter: These young women seem to understand what kids will do -- and share their concern with the bartender. ??? Happy birthday to you ??? She needs some water. Reporter: And their share their compassion with Madison. You want a few chips? Thank you. We have salsa too. Thank you. You're welcome. It will make you feel better. Reporter: But when Madison's friends leave, they learn their plan for the day. They just don't stop pressuring me to do this tradition. 21 shots. Oh hell no, not all at once. I've done that before it was not fun. Did you get sick? You don't have to do anything you don't want to do. You're 21. It's your birthday. And it's your birthday. You get to say what you want to do, you know? You're the queen of the day. You know? You make the rules today. Reporter: And now Madison stumbles to the bathroom. Watch my chips. Sure. Of course. Reporter: And one of the young girls follows her. I feel bad, they shouldn't be pressuring her. I'm like, the mom every time I see somebody like that, I give them water immediately. Are you okay? I think she might throw up. Oh, my god. She goes, "Hey, could you please just watch my chips?" Reporter: Hi, guys, how are you? I'm John Quinones. They were actors. You guys are young yourselves. I'm 22, she's 21. Reporter: Yeah. That doesn't give you a reason to be stupid. Yeah, what if that was us? Exactly. Like, if that was her and she was by herself, I would pray someone would be helping her. Reporter: What's the moral of the story here? Be your own person. Have your own opinions. Don't let anybody push you into
This transcript has been automatically generated and may not be 100% accurate.