It's happened to everybody: you break up with someone. A friendship falls apart. You leave your job, and, by extension, your coworkers. Over the course of your life, you'll probably acquire a lot of exes - romantic or otherwise. You know that you'll see these exes again eventually, but that doesn't make it any less awkward when it happens.

No matter how much you don't want to see these people again, you shouldn't run away from them or intentionally ignore them. That's just rude. And you're above that. You want to show that you're the bigger (wo)man in the situation, right? After the jump are a few situations in which you may run into an ex (of whatever nature), and how to handle them.

• You're walking toward each other on the street. Make eye contact. Give half a smile. Say hello. Don't look down and pretend you don't see the person walking toward you. That being said, you don't need to stop and talk to the person. A simple "hey" as you blow past each other is sufficient.
• You end up on the same bus/subway/train/trolley. This can be awkward, but remember: there are lots of seats on said modes of public transportation, so you don't have to sit next to your ex. If, for some reason, it does work out that way, make polite small talk. Don't ask about your replacement, whether it's a new significant other, friend, or coworker. If you have a book/newspaper/magazine with you, you may very politely ask if your ex minds if you read. If s/he has one, say, "I don't mean to interrupt you from [publication here]," and then stop talking until it's time for one of you to get off. Then say goodbye. Don't suggest that the other person call you if you don't mean it.
• You're in the same elevator. The key thing to remember here is that elevator rides tend to be pretty short. Say hello, talk about the weather, and get off the damned elevator as soon as you reach your floor - or thank god when your ex does.
• You end up standing in line behind your ex at the grocery store. If you can't stand the idea of staring at the back of your ex's head without saying something (it's hard, I know), a simple "Hey, how are you?" is probably plenty. Don't look in your ex's basket and say, "Steak, huh? You always made the best steak. Remember that time that we had Bob and Sue over for steak?" That, friends, is how to foster awkwardness. Don't ask what your ex is cooking or for whom. If you really need to talk about something, look to your right or your left. There's bound to be a tabloid there: talk about Britney Spears' latest bad parenting endeavors or Paris Hilton's desire to open a shelter for recently-released inmates. Keep it casual, and avoid the personal.
• You work together. First of all, what the hell were you doing dating a coworker in the first place? Secondly, short of quitting your job or trying to get your ex transferred, there's no way that you can avoid your ex, even a little - and you knew this when you started dating. When you do have to interact, and you will, keep the discussion to work-related matters only. Don't ask what's going on after work, or even how your ex's weekend was. You don't want to know, anyway: it didn't include you.
• You end up at a party together. Short of airing all your dirty laundry to the party's host and excusing yourself from attendance owing to the break-up, there's not a whole lot you can do here. You and your ex have a history, and, by extension, a lot of mutual friends. You will end up in the same small conversational cluster, and you will have to talk to each other. Whatever you do, avoid awkwardness, both amongst yourselves and for the group as a whole. Try to focus the talk on the others in the group. If your ex is dominating the conversation, wait for a lull and politely excuse yourself to another cluster, to the bathroom, or to the bar. But if you choose the latter, be sure you don't get sloppy drunk. Things can get embarrassing for you really fast. And speaking of alcohol and exes...
• Your ex is your bartender. Order top-shelf liquor and tip generously. Don't linger at the bar too long. If your bartending ex happens to be a romantic ex, don't try to pick up your evening's conquest at the bar. If possible, gather your friends and move on to another place: alcohol tastes the same wherever you drink it, but you might enjoy it better when you're not in the middle of an awkward situation.

Image via Flickr user 摩根.