“You need to be careful. I had a friend who recently mentioned to her coworker how she felt underpaid, and her coworker managed to extract all the details about her salary than receded to go to her boss demanding that she get paid like my friend….”
A boss should know how to deal with situations like that. If an employee feels he/she deserves a raise, he/she should have a more legitimate reason than “he gets paid more than me.” An employer has no obligation to pay all of his employees equally, even if they have similar qualifications.