My partner gets too into sports at events and acts like a goon. It's one thing to cheer for your team but now he heckles the opposing team's fans and I'm worried it'll escalate if he razzes the wrong person. What should I do?
Let him learn the hard way. Bam!
Heckling opposing fans isn't mere banter when it escalates to genuine provocation. You’re right to worry about the consequences of “razzing the wrong person.” In today’s world, simple verbal altercations at public events can tragically spiral out of control -- and land him on TMZ or going viral on social media. (Hey, have your camera ready, upload it and make a few bucks!)
Actually, that might be the starting point for having a discussion with him. "You know those people we see on TMZ...?" And then lead into how you don't want him to be that, or you being "that couple" that's mocked on everyone else's videos and subsequent posts. (Although, you haven't exactly said if you go with him but I assume you do since it sounds like you've witnessed it.)
If saying you don't want him to be "that guy" or you two being "that couple" has no impact, say you don't want to go to games with him anymore. Either he changes or he goes without you. His choice might actually be telling to demonstrate what means more to him: being a rowdy fan or pissing you off.
I'm not sure this is as a complex problem as you might think. It's really just as simple as saying what I've already outlined. If you can't do that, I question the communication in your relationship. Not to come down on you (well, maybe a little), but this is a simple, "Hey, knock it off" conversation.
If all else fails, maybe him taking a shot to the jaw by the heckled will make him change his approach.