Sherry Bennett
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Sherry Bennett was one of Gaius Baltar's previous sexual conquests. When asked about the first woman, excluding his mother, he ever lied to by his Internal Six, Baltar told her that it was Bennett.
When both, Bennett and Baltar were in fourth grade of elementary school, they played a game of "If you show me yours, I'll show you mine" behind the background in the band room of their school. She showed hers, whereas Gaius did not.
He believes he may have slept with her, "many years later, of course". According to Baltar, she turned out to be a "very beautiful" woman. (Water)