Can you play more than one expansion pack in The Sims 4?

so i have a dilemma,and really it's kinda stupid.

I wanted to play Get Together expansion pack along with Spa Day in my main game,but the guy at the shop said you can only play one expansion pack at once.

Basically,if i installed one,i would replace the previous one.

This is a huge disappointment for me because in the Sims 3 you could install as many as you like.

i'm sure i wouldn't want to be walking down the street one day with my club only to find my spa vanished from the world.

This is definitely the biggest decision i'd have to make,and installing them back and forth takes forever.

anyways,is it true? 

Or the guy just lied to me?