Some couples make up and break up like nobody’s business. No matter how often they say “we’re not going to get into an on-again, off-again situation,” it happens…repeatedly. If you have a friend who’s giving things another go with an ex, you may have tried to remind them of the ex’s faults, which led to the breakup in the first place. And if you’ve opened up your personal ex files for a second viewing, maybe you haven’t even clued in your besties for fear of not loving their reaction.

Well, according to experts, not every situation of rekindling lost love is doomed—after all, Carrie and Big did end up together after all those failed attempts. “Many couples get back together after a breakup,” says relationship expert Rachel Sussman, LCSW. “That’s totally normal. It’s not a good or a bad idea to get back with an ex.”

That said, there is one red flag to look for when you want to try again with someone familiar—and it’s not necessarily how much the two of you fight. “Partners bicker, and that’s not a bad thing,” says relationship expert Logan Levkoff, PhD. The real issue is the kinds of fights you’re weathering. “If the conflicts you’re having are the same ones you had before you broke up, that that’s probably not great,” she says. Sussman echoes that unresolved baggage is the top culprit she sees for relationship retries failing. “The real reason the couple broke up in the first place needs to be worked out in order for the relationship to flourish the second time around,” she explains. “If and when that doesn’t happen, the relationship will inevitably fail.”

“If the conflicts you’re having are the same ones you had before you broke up, that that’s probably not great.” —relationship expert Logan Levkoff, PhD

Couples break up for all kinds of reasons—big and small. But if the reason you broke up remains an unresolved issue, then you’re likely to just retread old territory. “The key to success in a rekindled relationship is growth for one or both partners,” Dr. Levkoff says. “If you guys haven’t grown, then things will likely continue on the way they did before you broke up.”

The rather unfortunate reality of about this one major red flag, though, is it might not immediately manifest. “There’s typically a honeymoon period when you get back with an ex,” Dr. Levkoff says, adding that the act of rekindling a relationship is comfortable, because there is familiarity there. But after a period time, just like in any new relationship, the honeymoon period wears off, and if the problems seem…familiar, it may be a sign of trouble ahead.

“Couples need to be realistic when getting back together,” Sussman says. “Sometimes it will work out. Sometimes it won’t. But the more hard work you put into something, the greater likelihood it will improve.” Though the same problems may exist, if both parties are willing to work toward an improved mutual future, working through the struggles may be possible. “Communication without defensiveness is super important during this phase,” Sussman says.

So, let’s say you get back together with an ex and old baggage abounds. Rather than flipping out and immediately calling it quits, Sussman says to take it as an opportunity for growth. “Figure out what went wrong and reset,” she says. You might wind up with a healthier relationship than before—with great new communication skills to boot.

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