A question!

Malky29184​  Yes, you can play both, but I wouldn't recommend it.  I see occasional issues with connected accounts, and with the game version from Epic or Steam overriding the EA App version and not allowing someone to play only through the EA App.  So I would strongly suggest not involving Epic at all.

It would be different if you had bought content through Epic, or Steam for that matter.  But if you haven't yet, then you don't need to give yourself a potential new headache here.

Sims 4 is free, permanently, on all platforms, so you're not passing up a limited-time opportunity.