Is your ex popping up out of the blue? Careful, they may be 'paperclipping' you.

You think you're finally over your ex. Until, out of nowhere, they slide into your DMs or send an unexpected text, suddenly wondering how you've been – only to disappear again.

It's not uncommon for a former partner to genuinely be interested in catching up with you. They may be curious about your post-breakup life or even attempt to rekindle the connection. But not every out-of-the-blue message is well-intentioned: Sometimes, toxic exes want to keep you on edge.

It's called "paperclipping," which describes when an ex reaches out intermittently, not because they're interested in you, but rather to keep you on the back burner as an option. It's similar to breadcrumbing, and it's intentional, often used by narcissists, according to relationship experts.

"It's when somebody has enough emotional intelligence to know what they're doing, but they also have high manipulative tendencies and a disregard for how their behaviors are affecting others," says clinical psychologist Carla Manly.

Paperclipping is problematic, because "it perpetuates the idea that people are disposable. That they're not individuals, but rather things to be objectified," she warns.

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What is 'paperclipping?' Here are the warning signs

According to Damona Hoffman, relationship coach and host of "The Dates and Mates" podcast, the dating trend is named after Clippy, the early-2000s annoying Microsoft pop-up that offered to "help" whenyou least expected or needed it. The same goes for an ex, who may follow up only to disappear again.

Typically, paperclipping involves "a lack of concern for your well-being," Manly says. "An ex who is truly checking in on you will respect your boundaries. However, people who are more manipulative will check in without being transparent about their intentions." Other signs include flakiness with no end-goal in mind (such as plans to meet in-person), as well as sporadic, random and non-meaningful conversations that don't move forward.

Why do people paperclip?

There isn't one answer. Sometimes, narcissists will use this tactic to maintain control over an ex who is no longer in their lives. Other times, it may stem from an avoidant style of attachment, describing someone who is fearful of connection and vulnerability. As a result, they resort to surface-level messages that leave former flings confused.

The common denominator, however, is that "it's driven from a singular focus on their own needs. So when they feel lonely or nostalgic, confused or are having a bad day, they need validation and pop back up to the people they think will give them that emotional exchange," Hoffman says, calling the dynamic "one-sided" and "selfish."

'Paperclipping' is toxic.

How could a simple "what's up?" be harmful?

To those on the receiving end, paperclipping may seem like an innocent, friendly gesture. But experts say it's often a strategic way to prevent someone from truly moving on.

"Popping out of the blue might bring back old feelings, and it can be very overwhelming if you're still healing from your ex," Hoffman says. "If they're not sincerely intending to repair what was broken, you're likely to fall into the same pattern of how your relationship played out."

Manly adds that this cycle of confusion can lead to problems including depression, anxiety, stress and trust issues in future relationships.

"The person who is being paperclipped doesn't know what is happening most of the time. So they're getting drawn back to someone from their past, and in most cases, the person is just pushed back to the side and discarded. They end up getting hurt, angry and confused," she says.

How to respond to an ex who is 'paperclipping' you

  • Ask yourself, have they made an effort to change? "You can go back to your ex 2, 3, 4, 5 times and unless they changed, the dynamic won't," Manly says.

  • Don't be afraid to call them out: Hoffman recommends pointing out that you've noticed their sporadic behaviors and to ask about their true intentions. "You can say, 'it's hard for me to be in touch with you, and I think we need some space' to set a clear boundary."

  • Or block them: Don't feel the need to respond to their outreach efforts. For some people, blocking or unfollowing may be the best solution if you feel you're being put on an emotional roller coaster.

Read more about toxic relationships

This article originally appeared on USA TODAY: 'Paperclipping': The latest toxic, dating trend to beware of