This reinforces the idea that jealousy stems from evolution and concerns about reproduction.
Men would want to know that their female partners' children are their own, which is why they would tend to worry more about their sexual infidelity than a male partner's.
Similarly women tend to worry about emotional infidelity, stemming from a time when they had to worry about men allocating resources to their relationship.
Under this theory, it makes sense that bisexual men dating women would be more worried about sexual infidelity than bisexual men dating men, who can't get pregnant, said study researcher Cory Scherer, a social psychologist at Pennsylvania State University Schuylkill.
Past research has suggested people in same-sex relationships worry more about the emotional aspects of cheating rather than sexual, Scherer said.
'Bisexuals kind of fit both aspects of this jealousy,' Scherer told LiveScience. 'You can make predictions of what kind of jealousy they may be distressed by depending on whom they're dating.'
Scherer and his colleagues recruited 134 self-identified bisexuals from lesbian, gay, bisexual and transgender organizations across the country to fill out an Internet questionnaire.
The survey asked the participants to imagine being cheated on and to identify the gender of the cheating partner.
They then had to choose whether they would be more upset about the sexual aspects of the cheating or the emotional betrayal.
The results of the study support the idea that a threat to reproduction helped lead to the evolution of jealousy
The answers showed that the men dating women were far more likely than other groups to be most stressed by sexual infidelity.
Among bisexual men dating women, 49 percent said they would be most bothered by the sex. For comparison, only 16 percent of men dating men said that the sex would bother them more than the emotional betrayal.
Women's concerns about infidelity weren't as affected by their partner's gender. Of women dating women, 25 percent said the sex would bother them more than the emotional infidelity, the same answer given by 17 percent of women dating men.
The researchers reported the results online in the Journal of Social and Personal Relationships.
The bisexual participants' answers support the idea that a threat to reproduction helped lead to the evolution of jealousy, Scherer said.
A man dating a man doesn't have to worry about accidentally raising another man's baby if his partner gets pregnant. But if that same man is dating a woman, he can't be entirely sure that any baby she has is his, which could have led to more anxiety about sexual fidelity.
One limitation of the study is that it didn't take into account the gender of the person the partner was cheating with, Scherer said.
That person's gender could complicate matters - for example, a man whose female partner cheated with another woman wouldn't have to worry about a surprise pregnancy, so perhaps emotional jealousy would become more important.