There's nothing less sexy than putting a number on how many times a month you and your partner should be having sex.

But in the Business Insider video above, psychotherapist and author M. Gary Neuman suggests that carving out time for sex may be the key difference between happily married couples and unhappily married ones.

While working on his "Creating Your Best Marriage" video series, Neuman and his team polled more than 400 women and found that unhappily married women had sex three to four times a month while happily married women had sex 11 times a month.

"Believe it or not, it was not about the satisfaction of the sex, it was about the frequency versus infrequency," he says of his 2009 research in the clip above.

So what's Neuman's best advice for fostering the kind of intimacy that leads to a little action between the sheets? First, you need to emotionally connect with your spouse.

"Sexuality in marriage is connected to the emotional connectedness of the spouses but sometimes that time needs to be planned out," Neuman told The Huffington Post. "Go out on a weekly date night and talk about anything except the three subjects you always discuss: money, work, and kids. Those conversations aren't what made you fall in love with each other and they won't sustain your love either."