They grow up so fast, even on a hit series like ABC's "Castle."
In season three, premiering on Sept. 20., mystery writer and crime-stopper Castle (Nathan Fillion) will have to deal with the ultimate foe -- his daughter Alexis brings home her first boyfriend.
Clearly it's not going to be an easy adjustment.
"You see someone with your daughter and something comes over you," Fillion tells PopcornBiz from the "Castle" season three premiere party. "Just imagine what happens when you walk into a living room and you see your daughter and her lip gloss is a little smeared and his hair is a little tussled."
"Try to imagine the face that comes over you. It's not going to be, 'Hey guys what's up?' " he adds. "It's going to be a look at the kid that says I can take you apart. And you can because you fight dirty."
Part of the problem might be that Castle is such a player with the ladies. Alexis (played by Molly C. Quinn) has always been the mature kid while her charismatic, philandering father knows how the male brain works.
"He's such a player himself that he doesn't want his daughter to get played," Quinn tells us. "So there's a lot of commotion."
There are a lot of parallels in the show's father-daughter relationship between the media-played out relationship of Bill and Chelsea Clinton ("that's actually a really good comparison," says Quinn. "There are a lot of the same qualities.")
Further, while Chelsea Clinton went for the Stanford brainiac in the boyfriend-turned-husband department instead of rebelling with a troublemaker, Alexis will make the same choice.
"Alexis goes for the smart, computer-hacker types," says Quinn. "There are no rockers."