The fourth character represented this flirtatious temptation, sort of a sexual force of nature. The ego character was just kind of going with the flow of the situation trying to figure out what the right thing to do was from moment to moment as the situation developed. The id character came off as a sex obsessed shallow loser and the ego character was disgusted by him. The superego character made the ego character feel guilty about the consequences on other people's feelings, not just guilty if I took a particular action but guilty that the situation (not created by me) even existed.
Basically, the superego character got rejected by her, the ego character rejected her because of his friendship with the superego character, and the id character nearly got laid (off-camera) and talked about it in offensive terms incessantly afterwards. The reason the id character didn't get laid was because she, knowing he was an asshole and being in control of the situation, was just playing him, using him.
The unanswered question is how she would have treated ego had superego not been part of the equation and ego not rejected her?