Tabloid reports that you’re a 300-pound preop transsexual are one thing — but try explaining them to your 7-year-old son. ”Parker, sadly, has just learned to read,” says headline grabber Rosie O’Donnell, who axed her mag, Rosie, on Sept. 18. ”He says to me at Target, ‘Mom, are you 300 lubs [that is, lbs.]?’ I go, ‘Honey, what is a lub?’ He goes, ‘It says right there you’re 300 lubs.’ I explained these magazines take a little bit of truth and then they lie.” Later, Parker asked if Mom was going to become a boy, and she said: ”Some people think girls should have long hair and boys should have short hair. You can have any kind of hair you want.” But an item claiming the family is falling apart was trickier. ”I go, ‘That one is a total lie and Mommy’s going to call the man who wrote it and tell him if he doesn’t fix it, he’s going to get in big trouble.”’