Translation:Are your parents also throwing a party?
kalas tends to be more food-centered and more likely to be for children, whereas fest tends to be more grownup and maybe more likely to involve dancing. Some combinations are used more often. födelsedagskalas 'birthday party' is more common than with -fest, kräftkalas 'crayfish party' is much more common than the version with -fest (although in this case, kräftskiva is the most established version). barnkalas 'children's party' is a set combination, and barnfest is rare. If I'd describe a 'samba party', I'd probably call it sambafest rather than sambakalas. But there's a lot of overlap.
Accepted answers with will at the moment are Will your parents also have/throw a party? Report other translations via the Report a problem -> My answer should be accepted button. Thank you for your help!