Their naked body might be on top of you — but their mind is on someone else.

A scandalous study has revealed that a jaw-dropping 49% of Americans in serious relationships admitted to frequently fantasizing about someone other than their partner while doing the deed.

Analysts from market research company OnePoll surveyed 2,000 sexually active adults for LELO, a luxury sex toy company, in an effort to explore current lovemaking trends, preference and behaviors in the United States. The study was released in August. 

“Intimacy is an evolving experience that benefits from adaptability and innovation,” said Luka Matutinovic, chief marketing officer at LELO, to SWNS. “Within the context of pleasure, achieving a satisfying experience requires a reasonable balance,” he continued. “A solid framework for a truly fulfilling encounter is formed by thoroughly examining one’s desires.”

Fantasizing about someone other than your main squeeze can be both a green and red flag that indicates your contentment in a relationship, said dating guru Jana Hocking. 

“The real question you have to ask yourself is, am I using this fantasy as a simple method for harmless enjoyment (I mean, we all have eyes and a throbbing libido …) or am I actually using it to escape my current boring love life?,” she wrote last June. 

“If you simply have a crush and just want to play make-believe for a little while, then heck, let your mind wander,” she said. “But if you haven’t been happy in your relationship for a while and you almost need to let your mind wander in order to climax, then perhaps it’s time to step back and have a proper look at the current state of your relationship.”

And while OnePoll’s discovery about the average sex partner’s wandering thoughts is shocking enough, that’s far from the report’s most eye-popping find. 

Researchers also determined that 61% of bedmates said they sometimes have sex because their partner wants to, even if they’re not in the mood — 71% of men, compared to 53% of women.

And although 73% of steady sweeties felt confident their other half was having a ball while getting busy, a measly 18% of the respondents — mostly men — said they “always” orgasm while doing the do. Only 15% of women reported that they regularly climax. One-in-eight of all those polled claimed they “rarely” or “never” achieve the big O. 

To help them hit the high note, however, 40% of both men and women copped to using sex toys in the sack, with 50% saying they’re hoping to explore a long-standing sexual desire with their partner soon. 

Matutinovic encourages folks who are toying around with the idea of spicing things up in the boudoir to do so for the sake of their happiness. 

“Integrating thoughtfully selected pleasure products into the intimate dynamic of a relationship can offer a substantial advantage,” said Matutinovic. 

“The introduction of sex toys in the bedroom introduces an element of novelty and variety, vital for sustaining long-term connections,” continued the adult plaything king. “By embracing these products, couples can embark on a journey of shared exploration, fostering enhanced communication and a deeper understanding of one another’s desires. 

He added, “In this pursuit, using sex toys can significantly contribute to maintaining a fulfilling and enduring bond.”

And NSFW trinkets may be just what the doctor ordered. 

In June, Emily Morse, a sex expert and author of “Smart Sex: How to boost your sex IQ and own your pleasure,” told The Post that sex toys were one of the tools that helped her go from constantly faking orgasms to having up to 23 a night. 

Elsewhere in the OnePoll study, fieldworkers learned that 30% of boinking lovebirds prefer foreplay over actual intercourse, 30% enjoy morning sex over midday or late night rolls in the hay and that 61% of the people who have sex four times a week still wish their sex lives were even more active. 

Matutinovic says the findings are meant to aid couples in boosting the benefits of boffing. 

“Our commitment to creating a seamless blend of satisfaction ensures that each intimate moment becomes a harmonious symphony of pleasure, highlighting the importance of mutual contentment,” he said. 

“It’s critical to remember that finding common ground between individual preferences and mutual enjoyment leads to a mutually enriching experience.”