A couple's counselor has been married for 52 years. These are her top relationship secrets.

• Barbara Grossman and her husband, Michael Grossman, work together as couple's coaches.
• She said the ups and downs of their 52-year marriage gave them the perfect background to give advice.
• Grossman shared their top three tips for making relationships last a lifetime.

Barbara Grossman wed her college sweetheart, Michael Grossman, in November 1971 when she was 20. He is one year older than her.

Now, at 72 and 73, the couple — who work together as relationship counselors — has 52 years of marriage behind them.

"We married very young and felt so much affinity; it looked like a very sweet, wonderful, smooth-sailing kind of thing," Dr. Barbara Grossman said.

"But you aren't fully formed in your early 20s and continue to develop. All relationships change as you mature."

Grossman said she started clashing with her husband when she reached her 30s. "We called it our 'power struggle phase,'" she told Business Insider.

She said the issue was mostly centered on her need to establish her identity outside her roles as a wife and mother.

"Michael worked long hours to build his career," she said, noting that his absence from home while she cared for their daughters fostered resentment. "I wanted more independence and self-expression," she added.

She said their arguments went nowhere because she would lash out in anger.

Fortunately, she said, they received couple's counseling from her mentor at the hospital where she worked. "He helped us understand that Michael needed to learn about feelings, and I needed to calm down," she said. "We had to listen to the other person's perspective and avoid rushing in with a counterargument or way to fix it ."

Grossman said the pair, who co-authored the book " Ageless Love: the Sexy Science of Falling In Love Forever , " uses the same techniques today. She recommended three of their most successful strategies for a successful marriage.

Share emotional baggage

Grossman said it's important for partners to discuss their life experiences from long before they met, especially their childhood.

"I encourage people to talk about their past because it usually reveals the historical reasons for their behavior, opinions, and attitudes," the doctor said.

"If you open up about situations — including unresolved feelings toward a family member, friend, or lover — it develops understanding, trust, and connection."

She said her bond with her husband strengthened after he told her about his strained relationship with his mother . In return, she told him about her fear of abandonment after not being raised by her biological father.

"I tell couples that your partnership is your opportunity to heal your past," Grossman said.

Carve out time for sex and togetherness

Grossman said that sex is paramount in every decade of marriage. "Being naked together nurtures your relationship," she said.

"It is good to have a regular prescription for love and intimacy, no matter how old you are. It is important in a way that our left brain doesn't understand."

She advocated for regular "date nights" when couples can share "what delights you both." The septuagenarian said that in their 60s, she and her husband discovered an interest that boosted their mutual attraction.

"Michael agreed to learn ballroom dancing because my grandmother was a professional dancer, and he knew it had always been my dream," Grossman, a grandmother of seven, said.

"It felt like the ultimate gesture of love, support and respect."

Air your grievances

According to Grossman, big differences in opinion need not lead to "all-out war."

"It's easy to dwell on the other person's mistakes and withdraw, amplifying the distance," she told BI.

She said the healthy choice was to stay centered and communicate how much hurt you felt and why.

"The only way to resolve a situation is to address it," she said. "People who stop and listen are more likely to realize their partner had the right to feel hurt.

"It takes time, but it will help them learn from their mistakes, change their behavior, and lead to forgiveness on both sides."

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