Fill in the blank: If your BF doesn't tell his family that he's dating you, it's probably because _____________.
If you answered, "He's not that into you," you're right! Too bad Jessica Simpson would likely fail that pop quiz. Jess better brush up on her guy knowledge (perhaps by reading Dude Decoder, Guy Guide, or Wise Guy, ahem), or she'll likely get burned by new BF, John Mayer.

Insiders say that while Jess has gone all puppy-dog since hooking up with the crooner, John's keeping it cool. In fact, John didn't even mention that he was dating Jess when he went to spend the holidays with his 'rents in Fairfield, Conn., In Touch reports. "Jessica didn't come up once in conversation," John's Dad, Richard, tells the mag. And while John's Dad insists his son is "very private" about his love life ("We never pry," he says), that still sounds a little suspicious. Don't say we didn't warn ya!