In This Corner: Mario Lopez vs. Matthew McConaughey

Round Two: The Jump-Off

Mario Lopez: he cheated on Karina Smirnoff for almost a year with Meagan Cooper, a Hooters waitress who also has a role in the upcoming reality show I Survived a Japanese Game Show.

Matthew McConaughey: he allegedly attempted to cheat on Camila by trying to sneak a kiss from a drunken tourist (who sold her story to a tabloid).

The Winner:
This one is easy. At least Matthew could try and use the lame "I was sooo drunk" excuse—but an entire year? A Hooters waitress who aspires to reach reality star fame? This one is Mario Lopez all the way.