General David Petraeus, 60, admitted to having an affair last week and resigned as head of the CIA. The retired four-star general’s mistress was his biographer, Paula Broadwell.  Petraeus and his wife, Holly, have been married 38 years and have two grown children.

But so many other powerful men have cheated on their wives: Bill Clinton, Herman Cain, John Edwards, Arnold Schwarzenegger … the list goes on and on.

Did the women in their lives miss the warning signs that their man was cheating?

Relationship expert Matt Titus says women, in general, will notice that, “The sexual frequency just plummets …he [also] gets jumpy around e-mails and cell phones.  He's always leaning into his computer or going on his phone when you're not around.  The mutual friends you have together -- they dissipate.”

Watch the full segment in the video player above.

Dr. Drew On Call airs Monday through Wednesday on HLN at 9 p.m. ET.  Follow the show on Facebook and Twitter @DrDrewHLN.

RELATED STORIES:

WATCH: CIA director David Petraeus resigns over affair

WATCH: Petraeus twists, shirtless pics, new players
 
PHOTOS: 11 politicians caught in cheating scandals