Leaving is often made harder by other cultural messages that mistake endurance with valor. “Many people have internalized the belief that staying, regardless of emotional cost, is a marker of their individual loyalty or strength,” says Pataky. As such, breaking up after many years can then feel like a personal failure.

Taken together, these beliefs can make it very difficult to ask the more meaningful question about the relationship—such as whether the relationship is still nourishing who they are today—let alone exit it.

The real costs of staying past the point of alignment

Ending a long-term relationship can feel like “throwing away” years of time and effort. But being in a relationship that no longer feels aligned with who you are and what you want can come at the cost of your mental and emotional well-being.

“Staying in a relationship primarily because of what you’ve already sunk into it requires ongoing self-betrayal,” says Pataky. Over time, suppressing your needs, emotions, and inner truth can erode self-trust and self-worth—both of which are foundational to mental health. That misalignment between internal experience (wanting to leave) and external reality (not leaving) can also show up as anxiety, depression, emotional numbing, or burnout, she says.

Unsatisfactory relationships can become more draining over time, says Heather Shannon, LCPC, CST, a licensed professional counselor, AASECT-certified sex therapist, and host of the Ask a Sex Therapist podcast. Stress and resentment often builds within relationships driven by sunk cost thinking, which increases within the relationship. Living in this state of heightened strain can lead people to feel irritable, trapped, and even hopeless, she says.

What else keeps people in sunk cost relationships?

Beyond sunk cost thinking, there are very real emotional, financial, and/or logistical factors that can make cutting off a relationship complicated.

On the emotional front, even if you recognize your relationship has passed its expiration, “leaving can feel destabilizing,” says Hertz. It often involves confronting feelings of loss, ambiguity, and grief, which all needed to be attended to, she says.