5 marriage mistakes couples make without realizing it — and how to avoid them

The secret to a happier, longer-lasting marriage may involve much more than chemistry and compatibility.

Recent research published in the journal Family Process found that improvements in communication and emotional safety were linked to greater relationship satisfaction.

Maintaining that connection takes effort, particularly as couples settle into routines and begin to feel as though they already know everything about each other, according to Tammy Nelson, Ph.D., a board-certified sexologist, sex therapist and integrative relationship therapist in Los Angeles. ‘FOOD DIVORCE’ TREND AMONG COUPLES COULD DRIVE THEM APART, EXPERTS WARN "Compatibility can feel different to different people at different times," she told Fox News Digital.

"The relationship will go through developmental stages just like you do." From losing curiosity to avoiding difficult conversations , Nelson shared five common mistakes that can weaken a couple’s connection — and ways to avoid them.

Losing curiosity about a partner can chip away at attraction over time, according to Nelson.

"That’s how we fall in love, when someone's curious about us," she said.

"When they come along and say, 'I'm so interested in you.

I'm curious about you.'" WHY COUPLES SHOULD FLIRT WITH EACH OTHER EVERY DAY — PLUS THE ‘RED FLAG’ TO AVOID "We're attracted to something in the space in between us — not so much when it's sitting next to us on the couch every night, and so we tend to lose that curiosity." While someone may feel they know everything about their partner — "what they like to eat, what they'd like to watch on TV, what they might like in bed" — those preferences can evolve over time, Nelson said.

"Don't put your partner in a box," Nelson said, urging couples to stay curious and ask questions.

"Who are they becoming? What are they thinking? What do they desire? What's their vision for the future?" POLITICAL FIGHTS CAN RIP COUPLES APART — THERAPIST SHARES 3 WAYS TO SAVE A RELATIONSHIP The therapist suggested that losing curiosity about a partner can sometimes make attention from someone outside the relationship particularly appealing.

"That's why we have affairs, right? Somebody comes along and they're fascinated by us," she said.

"We love that.

And it's why we pay a therapist, so someone will ask questions about us." Avoiding difficult conversations — and failing to pay attention to what goes unsaid — can create problems in a relationship, Nelson cautioned.

"Pay attention to what you're not talking about and why," she advised.