<P> In the first - season episode "The Fuzzy Boots Corollary", Penny describes her approach after a failed relationship: she picks up an attractive man to have rebound sex with over the course of a 36 - hour weekend, then leaves him . </P> <P> In the first - season finale, Penny breaks up with her boyfriend after he posts intimate details about their private life on his blog . This gives Leonard the opportunity to ask her out on a first official date . Although the date is successful, Penny becomes worried after she lies to Leonard about graduating from community college (it is mentioned in a later episode, "The Cohabitation Formulation", that she was enrolled in one, but dropped out). When Sheldon asks her why she lied, she indicates that she is self - conscious about her comparative level of education . Leonard eventually learns the truth, but makes matters worse when he tries to encourage Penny to enroll in Pasadena City College, as Penny interprets his suggestion as an insult to her intelligence, and rebuffs him . </P> <P> In "The Maternal Capacitance", Penny's introduction to Leonard's mother, Dr. Beverly Hofstadter, causes Penny and Leonard to seek comfort in each other . They nearly have sex, but when Leonard comments in bed that she was attracted to him because of a psychological need to be closer to her father, her revulsion at this causes her to rebuff him . </P> <P> Afterwards, Penny dates Stuart, from the comic book store, but their dates do not lead to a relationship . The first time, Penny and Stuart are interrupted by Sheldon, who argues at length with Stuart over whether Dick Grayson or Jason Todd should be Batman's successor, while Penny falls to sleep . Their dating ends in "The Classified Materials Turbulence", when Penny and Stuart are kissing, and Penny mistakenly calls him "Leonard". </P>

Who has penny slept with on big bang theory