I broke up with the woman that I'd been seeing for a little over three months. I really tried to want to date her more, but my heart wasn't in it. She was already integrated into my social network before we dated, but strengthened her role with all my friends while we were together. I don't want her to go away- she really is a great person- but she keeps making these underhanded remarks in group conversations. Her remarks are little cuts at me. There are so many layers to it that I can't just call her on every comment, but they all hurt. I did break up with her, so I guess a little of this is understandable, but it's been weeks. When is this going to stop? How can I hang out with everyone and not feel like I'm being attacked? Is there a way to get her to stop without blowing up at her in front of all my friends? I can't take this anymore.
Sounds like you bruised her ego pretty badly, not to mention her little heart. That aside, public ridicule can only go on for so long before it becomes unacceptable. Oh no wait, it's always unacceptable, but people get a pass among friends when they're hurt. So she thinks that she's a victim of your cold cold heart and can stab at you, evil ex-boyfriend, until you retreat or realize that she's the greatest and you want her back. Maybe she's trying to hurt you, and she thinks public humiliation is a perfect course of action for her closure. You humiliated her by not falling in love with her, so she things she's playing fair. Regardless of what she's convinced herself is acceptable, she needs to learn basic social decorum before she alienates you and all of her shiny new friends. Being in pain is hard, and I hope you can realize she's reacting to that pain. However, she would be happier to either remove herself from your immediate social life or learn to not react so publicly to the trespasses on her heart. The intimacy of pain is similar to the intimacy of love- private.
It is rather gracious of you not to try to pull rank on her, and make your friends pick sides. Also, shame on the friends for not noticing that fighting is progressively escalating in front of them, and they're doing nothing to stop it. You can rarely rely on your friends to help you clean up messes, but what they sometimes lack in leadership potential they usually make up in audience participation. You'll have to harness their reticent behavior for your own benefit.
At the next impasse of mean little comments, make a 'wincing in pain' face, turn to her and say in your most nonchalant voice, "Easy there tiger." Then get up, walk to the bar (because I assume you and your friends are at a bar), and order two beers. Your friends will take a moment to think about stepping in (but they probably won't), and she'll wonder if she went too far this time. You're speaking then leaving will cause tension and anxiety among the table. You, at the bar, need to take a deep breath, and return as the calming hero to this table. Hand her a beer, a mild peace offering, and say, "you seemed to need another one". Then sit back down, the victor, and start a new conversation about something that isn't your relationship with the woman of a thousand tiny cuts. You don't want to talk about the reasons you couldn't love her, and she doesn't want to make the same social mistake again. Effectively, you are putting her in her place, and saying enough is enough. But you'll do it as a gentleman, not as the jerk she's trying to portray you as. You have to act like you want her to act, as if nothing ever happened.
What beer to order? Oh yes, I knew this would come up. For you, I would recommend the Dogfishhead Raison d'Etre (trans. reason for living). It's a mahogany ale brewed with green raisons and beet sugar, and weighs in at about 8% abv. A delightful elixir from Dogfishhead brewery in Delaware, it may be hard to find on tap. If your local watering hole doesn't have Raison d'Etre, ask your bartender for something strong and malty. You need to keep that sweet taste in your mouth, and remember that you're trying to kill this problem with kindness. For her I'd also suggest something sweet. Keep everything sharp away from her, even the hops. This time of year, there are a ton of craft brewed Maibocks on draught. I would suggest the Stoudt's Maibock from Adamstown, Pennsylvania for its honey taste and 7% alcohol. Remember, by the time she finishes that beer, you want her to be happily chatting about whatever, not thinking about smashing the glass on the edge of the table and cutting your heart out. Don't worry, she'll move on soon enough. So will you.