updated 04/12/2011 AT 11:00 AM ET
•originally published 04/12/2011 AT 11:45 AM ET
The Tori & Dean: sTORIbook Weddings star says she and hubby Dean McDermott want to keep the sex of their baby a surprise.
“We’ve been blessed with a boy and girl already, so this time we’ve decided to do it the traditional way and not find out the sex,” Spelling, 37, tells PEOPLE.
Already mom to son Liam, 4, and daughter Stella, 2½, the reality star says her new addition will be joining an already boisterous brood.
“They are best friends but they are at that age where there’s that love-hate relationship,” Spelling told PEOPLE at the GLAAD Media Awards in Los Angeles recently. “[Liam] beats [Stella] up, and she just adores him.”
But by nightfall, all is forgotten. “They want to sleep in the same room,” Spelling said. “That’s their new thing.”
Reporting by MICHELLE WARD and ULRICA WIHLBORG