Peter, a medical intern from U.C.L.A. first appeared in a laundromat meeting Andrea Zuckerman, who was with her daughter, Hannah Zuckerman-Vasquez. Peter assumed that Andrea was the babysitter and flirted with her.
They later meet up again when Andrea took Hannah to the doctor with her husband, Jesse Vasquez. Peter admitted that he was married, but unhappily and regretted getting married so young.
Soon after that, Peter and Andrea started an affair. Dylan McKay, who was visiting with his friend Charlie Rollins from rehab, caught wind of their affair while they were at the hotel where Charlie worked. After Andrea proposed that she and Peter leave their spouses, Peter broke it off with her because his wife was putting him through medical school.