Love and the comfort zone: When do unpleasant habits backfire?

At the start of every relationship, both people put forth every effort to present the best version of themselves. Hair is clean and coifed, manners are accounted for and each person dresses to impress. But as several months pass and the couple grow closer, different people start to emerge.

Welcome to the world of sweatpants, messy hair and gross behaviors. Things you would normally do only in private — burping, eating like a slob, passing gas, picking your nose — you may feel free to do in front of the other person because you assume they will be fine with it.

But that isn't always the case.

"Ideally, you want to be able to push the margins and be completely comfortable and open with your partner, so that you could potentially keep the bathroom door open, go without makeup, belch, etc., but if that's the rule of thumb [all the] time, it can become a turnoff," said Jane Greer, a marriage and family therapist based in New York.

Sure, it's natural to let one's guard down and reveal the real you as the relationship evolves, but don't leave behind the person your partner fell for initially.

"Being yourself also includes consideration for the other person and showing them the best of you, in addition to the worst of you," Greer said. "You want your partner to feel that they are the most important person in your life — not the least."

Dr. Carole Lieberman, a psychiatrist and relationship expert based in Beverly Hills, Calif., said that before couples decide to let it all hang out, they should remember the phrase, "Familiarity breeds contempt."

Getting too "up close and personal" with a partner may also tempt a wandering eye. For instance, Lieberman said, "When you see other potential mates whose bodily functions you haven't been exposed to, they seem more alluring."

But Stan Tatkin, couples therapist in Calabasas, Calif., and an assistant clinical professor at the University of California at Los Angeles, said it is inevitable that with time the mystery and excitement surrounding a relationship will fade — no matter what two people do.

"There's no way to preserve that new car smell," he said. The way to keep the passion alive is to never stop paying attention to your partner. Continue to listen, to watch and to learn more about them every day, he said.

"You can't make yourself mysterious and have a secure relationship," Tatkin added. "But you can stay in love by being yourself and staying transparent."

What if both partners in a relationship are on board with getting up close and personal?

"I don't think anything really crosses the line," she said. "Everyone does all these things, so if you feel comfortable enough with each other, then it shouldn't stop you from being open about these usually private things."

But there is one activity — known to be a highly divisive issue for some couples — that she isn't 100 percent comfortable with yet.

"Sometimes I feel a bit weird about leaving the bathroom door open, but [my fiancé] always says, 'Don't worry, it's just me,' " Elisa said.

Couples should be upfront about what habits make them uncomfortable and voice that concern sooner rather than later, Lieberman recommended.

"It all depends on what is personally disgusting to you and your partner," Greer said. "If you find none of the things your partner does unappealing, there's no need to worry about being open and sharing them with your partner."