Secret stash?

Kayla
My husband and I share an account and money seems to go so fast! I just received a monetary gift from a relative and I'm thinking about either cashing it and hiding it or opening a new account. 
Ultimately I'm thinking of saving it for a surprise weekend getaway or something. 
Thoughts? 
Am I wrong to keep it from my husband. 
(Btw, he isn't the best with money. He's actually horrible with money.)