But before you freak out, know that her private lust for another man doesn't necessarily spell doom for your relationship. There's no scientific evidence that her thinking about cheating means she will actually stray.
Fantasies are just a way for her to indulge a primitive urge for sexual variety while staying true to you, says Dr Wendy Walsh, an adjunct professor of psychology at Cal State.
“Human beings are aroused by novelty and newness,” Walsh says. “It’s part of our anthropological mission to spread our seed. Sexual fantasies let her create that newness in her head—rather than in her bed.”
It doesn’t mean she loves you any less, Walsh says. In fact, it’ll help her stay committed by scratching that novelty itch without actually crossing any lines.
“Fantasies are the number one thing that help monogamy survive long term,” Walsh says.
And besides, you do the same thing all the time. According to the Vermont study, 98 per cent of men imagine having sex with other women. (The other 2 per cent are liars, we suspect.)
The bottom line: Don’t sweat it, says Dr Paul Hokemeyer, an NYC-based marriage therapist. “Appreciate the fact that she gets horny and desires a full and interesting sex life,” Hokemeyer says.
Remember, though, that fantasies aren’t the only way to keep sex exciting in a long-term relationship.
“Sometimes when couples are together for a long time, they get to know each others’ bodies so well that they play the same strings over and over,” says Walsh.
To bring the spark back, suggest something daring and totally out of character, says Dr Pepper Schwartz, professor of sociology and co-author of The Normal Bar. Try getting frisky in a semi-public place or asking her to go without panties for the day. Or even better, find out what's on her mind and work that into your repertoire, Hokemeyer says. Is she into cops or firemen? Go get yourself a uniform.
This article was originally published on MensHealth.com