Not all office romances are short-lived; 22 percent of respondents reported that they met their spouse or significant other this way. Hussam Hamadeh, Vault co-president, says workplace relationships cause minimal, if any, disruption as long as both parties exercise good judgment.

"There are companies that have anti-nepotism and dating policies, where a manager cannot date someone they supervise. Or, if they do, they have to inform the company, so the company can decide: Do they want to change the reporting relationship?" said [Paula Brantner], who is based in Kansas City, Mo. Some employers add another layer of protection by compelling both workers to sign an agreement as proof that "they're entering into a voluntary and consensual relationship."

Although both the boss and subordinate stand to lose if the romance ends, "the supervisor has more at stake," she said, because of corporate concerns about possible sexual harassment. "The company is more likely to be legally liable and face financial damages for what the supervisor does. So that's why the supervisor needs to be very candid."