One of the things that came out regarding the SS scandal was that it went sour at about 7:00 a.m. To me, it meant that the other women had probably already left. They could have had audio visual devices to record (or maybe even do live broadcast of their activities) for future blackmail. And, it is possible that one or more might have waited until an agent passed out and possibly photographed the entire security plan for Obama, thus compromising his safety and the safety of others.
These agents are "high value" intelligence targets. Their rooms could have been bugged from the beginning. And one has to assume that encounters with strangers which are not casual must be viewed as possible attempts to gain information. And I know I don't need to add this, but one of the most successful methods of getting information from men is the use of female agents.