6'2 and 175 is not that big....
...and some posters here are bigger and more manly. Fine, on that line of thought I'd have a little over a 40lb weight advantage, and only some of that is fat. I also have a pretty extensive H2H background (3 years wrestling, 2 years kempo and kenpo kickboxing, 9-10 years aikido; recently started studying arnis, to supplement the aikido). But so what?
Just because the odds are very high that I could tear a mouthy teen a new one, and frankly I could probably make a lasting impression on the three described in the OP's scenario, does not make it a good idea for me to do so.
Assuming I would even consider it if on my own, it would become out of question if I were out with my lady (who would be unhappy about the altercation) or my sister (who would either chew me out or kick my butt, or she'd just use her laser eyes on me) or my mother (one reason for that will be covered next).
Last time I got in a fight around one of the women in my family, the woman was my mother, I was 20, and there had been a traffic accident. Even then, I wasn't looking for a fight, but the other driver's boyfriend decided to attack me while we were waiting for the cops. He swung at me, I floored him with a straight right, and next thing I knew my right ear hurt. Turns out my mother came up and grabbed my earlobe, pulling me away and saying "don't kill him."
Did I mention my mother is Sicilian?
Anyway, the guy didn't try that again, but I'm not sure if he was more scared of me or my mother. Wish to this day that I had video of her dragging me back to the car by my earlobe.... The thought still makes me smile.
This brings up another point: While we big he-men may feel like we need to protect the womenfolk, I can't think of too many guys who would like the cans they'd be opening if they had provoked my mother back in the day, or my sister up to the present day. They don't need protecting, except from serious threats - muggers or rapists, sure, but not from some idiot loudmouth at a movie theater. I'm quite sure that my mother, my sister, and my significant other would feel that my actions in going after the idiots would reduce me to the level of said idiots, and reflect poorly on my companions. On the other hand, if the guys were real BG's, then my mother, sister, or significant other would either be scrambling to call 911 or else be all over the back of any BG who tried to get to my blind side. They'd probably do both.
My sister has probably put more guys on the floor than 75% of the posters in this forum. Taught her straight right, left hook, and uppercut when she was a pre-teen. She's used the uppercut successfully on three occasions that I know of...
My significant other breaks and trains horses. She's a sweetie, but she's strong and not easily intimidated by mammals under 1500lbs.
None of them are impressed by chest-thumping. For that matter, neither am I. If you want to impress the women in my pack, use your grey matter first, and use the knuckles only when there are no other choices.