Cheater: Roger Clemens
Date Of Affair: 1991- 2006

Like beleaguered Major Leaguer Roger Clemens needed any more problems. Already knee deep in baseball's worst drug scandal, the Red Sox star pitchers' alleged long-term, on-again, off-again relationship with another woman only compounded matters for Clemens. That secret significant other turned out to be country singer Mindy McCready, who apparently met the married-with-children Rocket in 1991 when she was just 15-year-olds singing karoke in a Florida bar. Although they spent the night together, McCready's dad told the New York Post that Rog was a "gentleman" and that their relationship didn't turn sexual until 1998 when his daughter broke up with Superman Dean Cain. Clemens never owned up to the relationship, but sources state that he continued to be there for Mindy as she went through a series of problems including being arrested for prescription fraud and subsequently serving time for violating probation when she allegedly hit her mother, as well as attempted suicide and a horrible beating by her son's father.