Why Some Male Members of Congress Won’t Be Alone with Female Staffers: Numerous women who work on the Hill say they've been excluded from solo meetings and evening events, a practice that could be illegal.

The National Journal reports:

It's no secret that Congress is dominated by men, but as women work to make inroads in the congressional boys club, some female staffers face a huge impediment to moving up: They're not allowed to spend one-on-one time with their male bosses.

In an anonymous survey of female staffers conducted by National Journal in order to gather information on the difficulties they face in a male-dominated industry, several female aides reported that they have been barred from staffing their male bosses at evening events, driving alone with their congressman or senator, or even sitting down one-on-one in his office for fear that others would get the wrong impression.

Some guys don't want to be accused of "having a relationship" a work.