Researchers from Cornell and Chicago Universities have linked impotence (erectile dysfunction) with social networks shared by heterosexual men and their partners.
They described the situation as "partner betweenness", wherein a man's wife has stronger relationships with his buddies than he himself does, American Journal of Sociology reports.
"Men who experience partner betweenness... are more likely to have trouble getting or maintaining an erection and are also more likely to experience difficulty achieving orgasm during sex," writes Prof Benjamin Cornwell, who led the study.
Prof Cornwell teaches sociology at Cornell University, who co-authored the study with his Chicago University counterpart Edward Laumann, according to a Cornell statement.
Cornwell and Laumann argue that partner betweenness erodes men's feelings of autonomy and privacy, undermining their masculinity. This can create overt conflict or problems with partner satisfaction and attraction.
They examined data from the National Social Life, Health and Ageing Project, a comprehensive survey at the University of Chicago that included 3,005 people, aged between 57 and 85 years.