David Arquette's son refuses to say his sister's name.

The 44-year-old actor has revealed 17-month-old Charlie, whom he has with his second wife Christina McLarty, has already struck up some sibling rivalry within the household as he won't refer to Coco, 11, by her first moniker.

Speaking to PEOPLE magazine, he said with a giggle: ''He's still holding off on saying [Coco's] name. He [Charlie] says everyone's name but hers. I think it's a power move. He's like, 'Wait a second, you're going to get attention too?' ''

However, Coco - David's first child from his marriage with ex-wife Courteney Cox - doesn't seem bothered by Charlie's games as she adores him and showers him with kindness.

David explained: ''She really loves him and is really kind to him. She is approaching adolescence, so there are some hormones that are starting to happen, but she has a great attitude, and she is really sweet.''

And it seems the youngsters are worlds apart personality-wise as little Charlie is obsessed with cars.

The handsome star added: ''Charlie's got his own personality. He's a little bit of a character.

''He loves cars, and our favourite game is 'Beep, Beep,' where I take him into my car and he flips all of the buttons. He will do that every day, 10 times a day. Every time he sees me he says, 'Beep, beep? Beep, beep?' ''